{{cite journal | last1=Azhar | first1=A. H. | author2=M. M. Alam | author3=M. Latif | year=2011 | title=SUBSURFACE DRAINAGE IMPACTS ON CROPPING INTENSITY IN PAKISTAN | journal=Journal of Animal and Plant Sciences | volume=21 | issue=1 | pages=97-103 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2011-JAPS-123}}