{{cite journal | last1=Ullah | first1=R. | author2=M. I. Lone | author3=K. S. Ullah | author4=S. M. Mehdi | author5=M. A. Qazi | year=2013 | title=EFFECT OF CROPPING SYSTEM AND SEASONAL VARIATION ON SOIL MICROBIAL BIOMASS AND ENZYMATIC ACTIVITIES IN ARID SOILS | journal=Journal of Animal and Plant Sciences | volume=23 | issue=2 | pages=493-499 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2013-JAPS-227}}