SPEC's documentation site utilizes a simple citation format to encourage contributors to always cite their sources. SPEC citation format leverages Gitbook's functionality.
Online Article or Blog Post
When the author name and publication date are known simply include the author's name, the title of the article configured as a link to page's URL, and the publication day (allowing for year only when exact date is unknown). For example for article Equality, Equality, and Reciprocity: The Three Pillars of Social Justice, written by Peter Corning on May 31, 2015.
When the individual author and publication date are unknown, but the research group or other publication entity is known. Include the research group name, title of the entry as a link to the URL, the overarching organization name, and last access date.
Wikipedia is one of the largest and most-read reference work in history. Wikipedia is a free, multilingual online encyclopedia written and maintained by a community of volunteers through a model of open collaboration, using a wiki-based editing system. Individual contributors, also called editors, are known as Wikipedians. For an entry citing a section from Wikipedia simply link the article include the anchor tag. For example for definition section of the Wikipedia entry on sustainability.