diff --git a/README-ja.md b/README-ja.md
index ce116705..0f003b2d 100644
--- a/README-ja.md
+++ b/README-ja.md
@@ -966,7 +966,7 @@ NoSQL は **key-value store**、 **document-store**、 **wide column store**、
 * [キーバリューデータベース](https://en.wikipedia.org/wiki/Key-value_database)
 * [キーバリューストアの欠点](http://stackoverflow.com/questions/4056093/what-are-the-disadvantages-of-using-a-key-value-table-over-nullable-columns-or)
 * [Redisアーキテクチャ](http://qnimate.com/overview-of-redis-architecture/)
-* [メムキャッシュアーキテクチャ](https://www.adayinthelifeof.nl/2011/02/06/memcache-internals/)
+* [メムキャッシュアーキテクチャ](https://adayinthelifeof.nl/2011/02/06/memcache-internals/)
 
 #### ドキュメントストア
 
@@ -1712,7 +1712,7 @@ Notes
 * [Facebook Engineering](https://www.facebook.com/Engineering)
 * [Flickr Code](http://code.flickr.net/)
 * [Foursquare Engineering Blog](http://engineering.foursquare.com/)
-* [GitHub Engineering Blog](http://githubengineering.com/)
+* [GitHub Engineering Blog](https://github.blog/category/engineering)
 * [Google Research Blog](http://googleresearch.blogspot.com/)
 * [Groupon Engineering Blog](https://engineering.groupon.com/)
 * [Heroku Engineering Blog](https://engineering.heroku.com/)
diff --git a/README-zh-Hans.md b/README-zh-Hans.md
index bb261ff4..368f588a 100644
--- a/README-zh-Hans.md
+++ b/README-zh-Hans.md
@@ -977,7 +977,7 @@ NoSQL 是**键-值数据库**、**文档型数据库**、**列型数据库**或*
 - [键-值数据库](https://en.wikipedia.org/wiki/Key-value_database)
 - [键-值存储的劣势](http://stackoverflow.com/questions/4056093/what-are-the-disadvantages-of-using-a-key-value-table-over-nullable-columns-or)
 - [Redis 架构](http://qnimate.com/overview-of-redis-architecture/)
-- [Memcached 架构](https://www.adayinthelifeof.nl/2011/02/06/memcache-internals/)
+- [Memcached 架构](https://adayinthelifeof.nl/2011/02/06/memcache-internals/)
 
 #### 文档类型存储
 
@@ -1723,7 +1723,7 @@ Notes
 * [Facebook Engineering](https://www.facebook.com/Engineering)
 * [Flickr Code](http://code.flickr.net/)
 * [Foursquare Engineering Blog](http://engineering.foursquare.com/)
-* [GitHub Engineering Blog](http://githubengineering.com/)
+* [GitHub Engineering Blog](https://github.blog/category/engineering)
 * [Google Research Blog](http://googleresearch.blogspot.com/)
 * [Groupon Engineering Blog](https://engineering.groupon.com/)
 * [Heroku Engineering Blog](https://engineering.heroku.com/)
diff --git a/README-zh-TW.md b/README-zh-TW.md
index 735323f5..d805e7e0 100644
--- a/README-zh-TW.md
+++ b/README-zh-TW.md
@@ -967,7 +967,7 @@ NoSQL 指的是 **鍵-值對的資料庫**、**文件類型資料庫**、**列
 * [鍵值對資料庫](https://en.wikipedia.org/wiki/Key-value_database)
 * [鍵值對資料庫的缺點](http://stackoverflow.com/questions/4056093/what-are-the-disadvantages-of-using-a-key-value-table-over-nullable-columns-or)
 * [Redis 架構](http://qnimate.com/overview-of-redis-architecture/)
-* [Memcached 架構](https://www.adayinthelifeof.nl/2011/02/06/memcache-internals/)
+* [Memcached 架構](https://adayinthelifeof.nl/2011/02/06/memcache-internals/)
 
 #### 文件類型資料庫
 
@@ -1713,7 +1713,7 @@ Notes
 * [Facebook Engineering](https://www.facebook.com/Engineering)
 * [Flickr Code](http://code.flickr.net/)
 * [Foursquare Engineering Blog](http://engineering.foursquare.com/)
-* [GitHub Engineering Blog](http://githubengineering.com/)
+* [GitHub Engineering Blog](https://github.blog/category/engineering)
 * [Google Research Blog](http://googleresearch.blogspot.com/)
 * [Groupon Engineering Blog](https://engineering.groupon.com/)
 * [Heroku Engineering Blog](https://engineering.heroku.com/)
diff --git a/README.md b/README.md
index 266f8b16..9d47277a 100644
--- a/README.md
+++ b/README.md
@@ -597,7 +597,7 @@ DNS is hierarchical, with a few authoritative servers at the top level.  Your ro
 
 Services such as [CloudFlare](https://www.cloudflare.com/dns/) and [Route 53](https://aws.amazon.com/route53/) provide managed DNS services.  Some DNS services can route traffic through various methods:
 
-* [Weighted round robin](https://www.g33kinfo.com/info/round-robin-vs-weighted-round-robin-lb)
+* [Weighted round robin](https://www.jscape.com/blog/load-balancing-algorithms)
     * Prevent traffic from going to servers under maintenance
     * Balance between varying cluster sizes
     * A/B testing
@@ -1015,7 +1015,7 @@ A key-value store is the basis for more complex systems such as a document store
 * [Key-value database](https://en.wikipedia.org/wiki/Key-value_database)
 * [Disadvantages of key-value stores](http://stackoverflow.com/questions/4056093/what-are-the-disadvantages-of-using-a-key-value-table-over-nullable-columns-or)
 * [Redis architecture](http://qnimate.com/overview-of-redis-architecture/)
-* [Memcached architecture](https://www.adayinthelifeof.nl/2011/02/06/memcache-internals/)
+* [Memcached architecture](https://adayinthelifeof.nl/2011/02/06/memcache-internals/)
 
 #### Document store
 
@@ -1764,7 +1764,7 @@ Handy metrics based on numbers above:
 * [Facebook Engineering](https://www.facebook.com/Engineering)
 * [Flickr Code](http://code.flickr.net/)
 * [Foursquare Engineering Blog](http://engineering.foursquare.com/)
-* [GitHub Engineering Blog](http://githubengineering.com/)
+* [GitHub Engineering Blog](https://github.blog/category/engineering)
 * [Google Research Blog](http://googleresearch.blogspot.com/)
 * [Groupon Engineering Blog](https://engineering.groupon.com/)
 * [Heroku Engineering Blog](https://engineering.heroku.com/)