A citation for a blog post has "Blog post" in square brackets after title. Notice that the titles of blog posts are not italicized.
Template:
Author, A. A. (Year, Day Month). Title of blog post [Blog post]. Retrieved from http://...
Example:
Perelman, D. (2012, November 26). Sweet potato cake with marshmallow frosting [Blog post]. Retrieved from http://smittenkitchen.com/blog/2013/11/sweet-potato-cake-with-marshmallow-frosting
If the blogger uses a screen name but you know their real name, alphabetize the reference by the real name and put the screen name in square brackets.
Template:
Author, A. A. [Screen Name]. (Year, Day Month). Title of blog post [Blog post]. Retrieved from http://...
Example:
Whitehead, T. [librariantiff].(2012, September 23). Nothing like the scent of a new book…[Blog post]. Retrieved from http://www.mightylittlelibrarian.com/?author=1&paged=4
If the blogger uses a screen name and you do not know their real name, alphabetize the reference by the screen name.
Template:
Screen Name. (Year, Day Month). Title of blog post [Blog post]. Retrieved from http://xxxxxxxx
Example:
liberal japonicus. (2013, September 29). Sabotage and Obamacare [Blog post]. Retrieved from http://obsidianwings.blogs.com/obsidian_wings/page/4