How to recognize different kinds of documents

Nowadays, books and articles aren't anymore the only ways for researchers to communicate their findings. Often it's possibile to find interesting contents even in blogs, web pages, posts on scientific social networks like ResearchGate or Academia.edu. 

When citing these materials, be careful to check the content.

Always report the link, the author, the publication date, and the access date, whereas other citation elements may not always be available.