remove wrong format symbol

resources/noat.cards/Application layer.md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/feeb549c5b6e94f65c613635f7166dc26e0c7de7/687474703a2f2f692e696d6775722e636f6d2f7942355359776d2e706e67) 
 
-_[Source: Intro to architecting systems for scale](http://lethain.com/introduction-to-architecting-systems-for-scale/#platform_layer) _
+[Source: Intro to architecting systems for scale](http://lethain.com/introduction-to-architecting-systems-for-scale/#platform_layer)
 
 Separating out the web layer from the application layer (also known as platform layer) allows you to scale and configure both layers independently. Adding a new API results in adding application servers without necessarily adding additional web servers.
 

resources/noat.cards/Availability patterns.md

@@ -35,7 +35,7 @@ The master serves reads and writes, replicating writes to one or more slaves, wh
 
 ![](https://camo.githubusercontent.com/6a097809b9690236258747d969b1d3e0d93bb8ca/687474703a2f2f692e696d6775722e636f6d2f4339696f47746e2e706e67) 
 
-_[Source: Scalability, availability, stability, patterns](http://www.slideshare.net/jboner/scalability-availability-stability-patterns/) _
+[Source: Scalability, availability, stability, patterns](http://www.slideshare.net/jboner/scalability-availability-stability-patterns/)
 
 ## Disadvantage(s) : master-slave replication
 
@@ -47,7 +47,7 @@ _[Source: Scalability, availability, stability, patterns](http://www.slideshare.
 Both masters serve reads and writes and coordinate with each other on writes. If either master goes down, the system can continue to operate with both reads and writes.
 
 ![](https://camo.githubusercontent.com/5862604b102ee97d85f86f89edda44bde85a5b7f/687474703a2f2f692e696d6775722e636f6d2f6b7241484c47672e706e67) 
-_[Source: Scalability, availability, stability, patterns](http://www.slideshare.net/jboner/scalability-availability-stability-patterns/) _
+[Source: Scalability, availability, stability, patterns](http://www.slideshare.net/jboner/scalability-availability-stability-patterns/)
 
 ## Disadvantage(s) : master-master replication
 

resources/noat.cards/Cache-aside.md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/7f5934e49a678b67f65e5ed53134bc258b007ebb/687474703a2f2f692e696d6775722e636f6d2f4f4e6a4f52716b2e706e67) 
 
-_[Source: From cache to in-memory data grid](http://www.slideshare.net/tmatyashovsky/from-cache-to-in-memory-data-grid-introduction-to-hazelcast) _
+[Source: From cache to in-memory data grid](http://www.slideshare.net/tmatyashovsky/from-cache-to-in-memory-data-grid-introduction-to-hazelcast)
 
 The application is responsible for reading and writing from storage. The cache does not interact with storage directly. The application does the following:
 

resources/noat.cards/Cache.md

@@ -9,7 +9,7 @@ isdraft = False
 ## Cache - Introduction
 ![](https://camo.githubusercontent.com/7acedde6aa7853baf2eb4a53f88e2595ebe43756/687474703a2f2f692e696d6775722e636f6d2f51367a32344c612e706e67) 
 
-_[Source: Scalable system design patterns](http://horicky.blogspot.com/2010/10/scalable-system-design-patterns.html) _
+[Source: Scalable system design patterns](http://horicky.blogspot.com/2010/10/scalable-system-design-patterns.html)
 
 Caching improves page load times and can reduce the load on your servers and databases. In this model, the dispatcher will first lookup if the request has been made before and try to find the previous result to return, in order to save the actual execution.
 

resources/noat.cards/Communication.md

@@ -2,4 +2,4 @@
 -------------
 ---
 ![](https://camo.githubusercontent.com/1d761d5688d28ce1fb12a0f1c8191bca96eece4c/687474703a2f2f692e696d6775722e636f6d2f354b656f6351732e6a7067) 
-_[Source: OSI 7 layer model](http://www.escotal.com/osilayer.html) _
+[Source: OSI 7 layer model](http://www.escotal.com/osilayer.html)

resources/noat.cards/Content delivery network.md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/853a8603651149c686bf3c504769fc594ff08849/687474703a2f2f692e696d6775722e636f6d2f683954417547492e6a7067) 
 
-_[Source: Why use a CDN](https://www.creative-artworks.eu/why-use-a-content-delivery-network-cdn/) _
+[Source: Why use a CDN](https://www.creative-artworks.eu/why-use-a-content-delivery-network-cdn/)
 
 A content delivery network (CDN) is a globally distributed network of proxy servers, serving content from locations closer to the user. Generally, static files such as HTML/CSS/JSS, photos, and videos are served from CDN, although some CDNs such as Amazon's CloudFront support dynamic content. The site's DNS resolution will tell clients which server to contact.
 

resources/noat.cards/Database.md

@@ -11,7 +11,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/15a7553727e6da98d0de5e9ca3792f6d2b5e92d4/687474703a2f2f692e696d6775722e636f6d2f586b6d3543587a2e706e67) 
 
-_[Source: Scaling up to your first 10 million users](https://www.youtube.com/watch?v=vg5onp8TU6Q) _
+[Source: Scaling up to your first 10 million users](https://www.youtube.com/watch?v=vg5onp8TU6Q)
 
 
 A relational database like SQL is a collection of data items organized in tables.

resources/noat.cards/Domain name system.md

@@ -8,7 +8,7 @@ isdraft = False
 ## Introduction Domain Name System
 
 ![](https://camo.githubusercontent.com/fae27d1291ed38dd120595d692eacd2505cd3a9c/687474703a2f2f692e696d6775722e636f6d2f494f794c6a34692e6a7067)
-_[Source: DNS security presentation](http://www.slideshare.net/srikrupa5/dns-security-presentation-issa) _
+[Source: DNS security presentation](http://www.slideshare.net/srikrupa5/dns-security-presentation-issa)
 
 A Domain Name System (DNS) translates a domain name such as [www.example.com](http://www.example.com/)  to an IP address.
 

resources/noat.cards/Federation.md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/6eb6570a8b6b4e1d52e3d7cc07e7959ea5dac75f/687474703a2f2f692e696d6775722e636f6d2f553371563333652e706e67) 
 
-_[Source: Scaling up to your first 10 million users](https://www.youtube.com/watch?v=vg5onp8TU6Q)_
+[Source: Scaling up to your first 10 million users](https://www.youtube.com/watch?v=vg5onp8TU6Q)
 
 Federation (or functional partitioning) splits up databases by function. For example, instead of a single, monolithic database, you could have three databases: forums,users, and products, resulting in less read and write traffic to each database and therefore less replication lag. Smaller databases result in more data that can fit in memory, which in turn results in more cache hits due to improved cache locality. With no single central master serializing writes you can write in parallel, increasing throughput.
 

resources/noat.cards/Graph database.md

@@ -10,7 +10,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/bf6508b65e98a7210d9861515833afa0d9434436/687474703a2f2f692e696d6775722e636f6d2f664e636c3635672e706e67) 
 
-_[Source: Graph database](https://en.wikipedia.org/wiki/File:GraphDatabase_PropertyGraph.png)_
+[Source: Graph database](https://en.wikipedia.org/wiki/File:GraphDatabase_PropertyGraph.png)
 
 
 In a graph database, each node is a record and each arc is a relationship between two nodes. Graph databases are optimized to represent complex relationships with many foreign keys or many-to-many relationships.

resources/noat.cards/Load balancer.md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/21caea3d7f67f451630012f657ae59a56709365c/687474703a2f2f692e696d6775722e636f6d2f6838316e39694b2e706e67) 
 
-_[Source: Scalable system design patterns](http://horicky.blogspot.com/2010/10/scalable-system-design-patterns.html)_
+[Source: Scalable system design patterns](http://horicky.blogspot.com/2010/10/scalable-system-design-patterns.html)
 
 Load balancers distribute incoming client requests to computing resources such as application servers and databases. In each case, the load balancer returns the response from the computing resource to the appropriate client. Load balancers are effective at:
 

resources/noat.cards/Remote procedure call (RPC).md

@@ -4,7 +4,7 @@
 
 ![](https://camo.githubusercontent.com/1a3d7771c0b0a7816d0533fffeb6eeeb442d9945/687474703a2f2f692e696d6775722e636f6d2f6946344d6b62352e706e67) 
 
-_[Source: Crack the system design interview](http://www.puncsky.com/blog/2016/02/14/crack-the-system-design-interview/)_
+[Source: Crack the system design interview](http://www.puncsky.com/blog/2016/02/14/crack-the-system-design-interview/)
 
 In an RPC, a client causes a procedure to execute on a different address space, usually a remote server. The procedure is coded as if it were a local procedure call, abstracting away the details of how to communicate with the server from the client program. Remote calls are usually slower and less reliable than local calls so it is helpful to distinguish RPC calls from local calls. Popular RPC frameworks include [Protobuf](https://developers.google.com/protocol-buffers/) , [Thrift](https://thrift.apache.org/) , and [Avro](https://avro.apache.org/docs/current/) .
 

resources/noat.cards/Reverse proxy (web server).md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/a66e9f885b04db69638825c6a98f42e5570a83f3/687474703a2f2f692e696d6775722e636f6d2f7037784853345a2e706e67) 
 
-_[Source: Wikipedia](https://commons.wikimedia.org/wiki/File:Proxy_concept_en.svg) _   
+[Source: Wikipedia](https://commons.wikimedia.org/wiki/File:Proxy_concept_en.svg)
 
 A reverse proxy is a web server that centralizes internal services and provides unified interfaces to the public. Requests from clients are forwarded to a server that can fulfill it before the reverse proxy returns the server's response to the client.
 

resources/noat.cards/Transmission control protocol (TCP).md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/821620cf6aa83566f4def561e754e5991480ca8d/687474703a2f2f692e696d6775722e636f6d2f4a6441736476472e6a7067) 
 
-_[Source: How to make a multiplayer game](http://www.wildbunny.co.uk/blog/2012/10/09/how-to-make-a-multi-player-game-part-1/)_
+[Source: How to make a multiplayer game](http://www.wildbunny.co.uk/blog/2012/10/09/how-to-make-a-multi-player-game-part-1/)
 
 TCP is a connection-oriented protocol over an [IP network](https://en.wikipedia.org/wiki/Internet_Protocol) . Connection is established and terminated using a [handshake](https://en.wikipedia.org/wiki/Handshaking) . All packets sent are guaranteed to reach the destination in the original order and without corruption through:
 

resources/noat.cards/User datagram protocol (UDP).md

@@ -9,7 +9,7 @@ isdraft = False
 
 ![](https://camo.githubusercontent.com/47eb14c0a2dff2166f8781a6ce8c7f33d4c33da8/687474703a2f2f692e696d6775722e636f6d2f797a44724a74412e6a7067) 
 
-_[Source: How to make a multiplayer game](http://www.wildbunny.co.uk/blog/2012/10/09/how-to-make-a-multi-player-game-part-1/) _
+[Source: How to make a multiplayer game](http://www.wildbunny.co.uk/blog/2012/10/09/how-to-make-a-multi-player-game-part-1/)
 
 UDP is connectionless. Datagrams (analogous to packets) are guaranteed only at the datagram level. Datagrams might reach their destination out of order or not at all. UDP does not support congestion control. Without the guarantees that TCP support, UDP is generally more efficient.