#{ Java: Colecciones, listas, mapas, etc. }

http://www.codercorp.com/blog/java/why-concurrenthashmap-is-better-than-hashtable-and-just-as-good-hashmap.html
http://javarevisited.blogspot.com/2010/10/difference-between-hashmap-and.html
http://stackoverflow.com/questions/40471/differences-between-hashmap-and-hashtable
http://stackoverflow.com/questions/1361784/hashmap-and-hashtable-in-multithreaded-environment
http://www.coderanch.com/t/374477/java/java/Books-java-collections-framework