{{cite journal | last1=Ser | first1=Gazel | year=2012 | title=DETERMINATION OF APPROPRIATE COVARIANCE STRUCTURES IN RANDOM SLOPE AND INTERCEPT MODEL APPLIED IN REPEATED MEASURES | journal=Journal of Animal and Plant Sciences | volume=22 | issue=3 | pages=552-555 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2012-JAPS-304}}