[1] Calendar API ( (2011-04-20 00:20:10 +09:00 版)) <http://www.w3.org/TR/2011/WD-calendar-api-20110419/>

[2] Calendar API ( (2012-10-02 20:46:33 +09:00 版)) <http://dev.w3.org/2009/dap/calendar/>

[3] Calendar API ( (2014-01-10 22:23:09 +09:00 版)) <http://www.w3.org/TR/2014/NOTE-calendar-api-20140114/>