Basic format (from apastyle.org) :
Author, A. (date). Title of document [Format description]. Retrieved from http://URL
That format description in brackets is used only when the format is something out of the ordinary, such as a blog post or lecture notes; otherwise, it's not necessary.
Note: According to the Publication Manual of the American Psychological Association 4.21, italicize a title when the document stands alone (books, reports, etc.) but not when it is part of a greater whole (chapters, articles, etc.) For example, use italics for the following:
American Psychological Association. (2010). Today’s superheroes send wrong image to boys, say researchers [Press release]. Retrieved from http://www.apa.org/news/press/releases/2010/08/macho-stereotype-unhealthy.aspx
The White House, Office of the Press Secretary. (2010). Administration officials continue travel across the country holding “Recovery Summer” events, project site visits [Press release]. Retrieved from http://www.whitehouse.gov/the-press-office/administration-officials-continue-travel-across-country-holding-recovery-summer-eve
King Fish Media. (2010). The perfect marriage of content and technology: Is social media the new CRM? [Press release]. Retrieved from http://www.prnewswire.com/news-releases/the-perfect-marriage-of-content-and-technology--is-social-media-the-new-crm-100760344.html
Note: Titles for items in online communities (e.g. blogs, newsgroups, forums) are not italicized.
Freakonomics. (2010, October 29). E-ZPass is a life-saver (literally) [Blog post]. Retrieved from http://freakonomics.blogs.nytimes.com/2010/10/29/e-zpass-is-a-life-saver-literally/
Barack Obama. (2009a, October 9). Humbled. http://my.barackobama.com/page/community/post/obamaforamerica/gGM45m [Facebook update]. Retrieved from http://www.facebook.com/posted.php? id=6815841748&share_id=154954250775&comments=1#s154954250775
Barack Obama. (2009b, July 15). Launched American Graduation Initiative to help additional 5 mill. Americans graduate college by 2020: http://bit.ly/gcTX7 [Twitter post]. Retrieved from http://twitter.com/BarackObama/status/2651151366
According to the Publication Manual of the American Psychological Association -- 6.20, personal communications such as:
are not included in the reference list. Cite them in text only (see examples in in-text citation)
Example of citing an email in the main text:
(G. Brown, personal communication, January 4, 2016).
For archival or recoverable documents, use the following format (from Publication Manual of the American Psychological Association --7.10) :
Author, A.A. (Year, Month Day). Title of material. [Description of material]. Name of Collection (Call number, Box number, File name or number, etc.). Name of Repository, Location.
According to the American Psychology Association website https://www.apastyle.org
Author, A. A. [Screen name]. (year, month day). Title of video [Video file]. Retrieved from http://xxxxxxxxx
Screen name. (year, month day).Title of video [Video file]. Retrieved from http://xxxxxxxxx
The in-text citations include the author name outside of brackets (whichever that may be) and the date.