Citing this Article
 

Owing to the fact that a Living Reviews article may evolve over time, we recommend to cite the article as follows:

Dimitrios Psaltis ,
"Probes and Tests of Strong-Field Gravity with Observations in the Electromagnetic Spectrum",
Living Rev. Relativity 11,  (2008),  9. URL (cited on <date>):
http://www.livingreviews.org/lrr-2008-9

The date given as <date> then uniquely identifies the version of the article
you are referring to.