Owing to the fact that a Living Reviews in Relativity article may evolve over time, we recommend to cite the article as follows:
Masaru Shibata and Keisuke Taniguchi,
"Coalescence of Black Hole-Neutron Star Binaries",
Living Rev. Relativity 14, (2011), 6. URL (accessed <date>):
http://www.livingreviews.org/lrr-2011-6
The date given as <date> then uniquely identifies the version of the article you are referring to.