{{cite journal | last1=Sadiq | first1=S. A. | author2=D. M. Baloch | author3=N. Ahmed | author4=Hidayatullah | year=2014 | title=ROLE OF COAL-DERIVED HUMIC ACID IN THE AVAILABILITY OF NUTREINTS AND GROWTH OF SUNFLOWER UNDER CALCAREOUS SOIL | journal=Journal of Animal and Plant Sciences | volume=24 | issue=6 | pages=1737-1742 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2014-JAPS-249}}