[1] Opera ヘルプ: エクステンション(拡張機能) ( (2011-02-07 19:27:16 +09:00 版)) http://help.opera.com/Linux/11.01/ja/extensions.html

[2] Opera: Opera Extensions API guides ( (Frank M. Palinkas, Technical Writer 著, 2011-08-06 22:56:05 +09:00 版)) http://www.opera.com/docs/apis/extensions/

[3] Welcome! - Opera 15+ extensions documentation (2015-03-14 01:51:40 +09:00 版) https://dev.opera.com/extensions/