The elements of the reference are as follows:
“who”: This is usually one or two people but can also be a company name or other type of group author. In the first example below, the post was credited to just “Freakonomics” (a screen name for the author or authors of the blog by the same name). If a byline is not evident, look at the beginning or end of the post for wording like “posted by.”
“when”: Blog posts generally provide the year, month, and date. Include these within the parentheses in your reference. If the blog doesn’t give that level of detail, just include the year or year and month, if that’s all you can find. (Note that your in-text citation will include only the year; see the examples below).
“what”: This it the title of the blog post followed by a notation of “[Blog post].”
“where”: Use “Retrieved from” and the URL of the blog post.