http://en.wikipedia.org/wiki/Singleton_pattern

Java Singleton in Practice #2

Ternyata ada juga singleton dengan hashtable. menarik

http://radio-weblogs.com/0122027/stories/2003/10/20/implementingTheSingletonPatternInJava.html

Java Singleton in Practice

Ini contoh penggunaan pattern singleton di java dan sedikit hack tentang clone object.

http://www.javacoffeebreak.com/articles/designpatterns/index.html