{{cite journal | last1=Khan | first1=M. B. | author2=R. Rafiq | author3=M. Hussain | author4=M. Farooq | author5=K. Jabran | year=2012 | title=RIDGE SOWING IMPROVES ROOT SYSTEM, PHOSPHORUS UPTAKE, GROWTH AND YIELD OF MAIZE (Zea mays L.) HYBRIDS | journal=Journal of Animal and Plant Sciences | volume=22 | issue=2 | pages=309-317 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2012-JAPS-212}}