Owing to the fact that a Living Reviews in Relativity article may evolve over time, we recommend to cite the article as follows:
Marek A. Abramowicz and P. Chris Fragile,
"Foundations of Black Hole Accretion Disk Theory",
Living Rev. Relativity 16, (2013), 1. URL (accessed <date>):
http://www.livingreviews.org/lrr-2013-1
The date given as <date> then uniquely identifies the version of the article you are referring to.