Owing to the fact that a Living Reviews in Relativity article may evolve over time, we recommend to cite the article as follows:
B.S. Sathyaprakash and Bernard F. Schutz,
"Physics, Astrophysics and Cosmology with Gravitational Waves",
Living Rev. Relativity 12, (2009), 2. URL (accessed <date>):
The date given as <date> then uniquely identifies the version of the article you are referring to.