{{cite journal | last1=Shahid | first1=B. | author2=M. I. Khan | author3=S. M. H. Andrabi | author4=A. Razzaq | author5=M. N. Khan | year=2019 | title=ESTRUS DURATION AND EXPRESSION IN NATURAL AND INDUCED ESTRUS IN INDIGENOUS (B os indicus) CATTLE | journal=Journal of Animal and Plant Sciences | volume=29 | issue=3 | pages=645-649 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2019-JAPS-302}}