@book{6385,
	author = {Bijleveld, Catrien C. J. H. and Kamp, Leo J. Th. van der.},
	title = {Longitudinal data analysis :},
	publisher = {SAGE Publication,},
	year = {1998.},
	address = {London :},
	url = {http://www.loc.gov/catdir/enhancements/fy0656/98061162-d.html}
}