{{cite journal | last1=Usman | first1=`M. | author2=S. Noureen | author3=B. Fatima | author4=Q. Zaman | year=2014 | title=LONG DAYS FOSTER CALLOGENESIS IN SPINACH AND LETTUCE CULTIVARS | journal=Journal of Animal and Plant Sciences | volume=24 | issue=2 | pages=585-591 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2014-JAPS-82}}