{{cite journal | last1=Javaid | first1=A. | author2=T. Riaz | year=2007 | title=SPREAD OF AGGRESSIVE ALIEN WEED PARTHENIUM HYSTEROPHORUS L. IN DISTRICT OKARA, PAKISTAN | journal=Journal of Animal and Plant Sciences | volume=17 | issue=4 | pages=NA | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2007-JAPS-409}}