[1] RFC 4791 - Calendaring Extensions to WebDAV (CalDAV) (2017-09-24 16:22:36 +09:00) https://tools.ietf.org/html/rfc4791

[2] RFC 6638 - Scheduling Extensions to CalDAV ( (2012-07-24 11:19:02 +09:00 版)) http://tools.ietf.org/html/rfc6638

[3] RFC 7809 - Calendaring Extensions to WebDAV (CalDAV): Time Zones by Reference (2016-04-02 09:16:11 +09:00 版) https://tools.ietf.org/html/rfc7809

[4] RFC Errata Report » RFC Editor (2017-10-01 21:26:57 +09:00) https://www.rfc-editor.org/errata_search.php?rfc=4791