@inbook{Snijders2008,
author = {Snijders, T.  and Berkhof, J. },
title= {Diagnostic checks for multilevel models},
year = {2008},
editor = {de Leeuw, J.},
editor = {Meijer, E. },
booktitle = {Handbook of multilevel analysis},
address = {New York},
publisher = {Springer},
pages = {139--173},
}