Owing to the fact that a Living Reviews in Relativity article may evolve over time, we recommend to cite the article as follows:
Ingrid H. Stairs,
"Testing General Relativity with Pulsar Timing",
Living Rev. Relativity 6, (2003), 5. URL (cited on <date>):
http://www.livingreviews.org/lrr-2003-5
The date given as <date> then uniquely identifies the version of the article you are referring to.