Collings, G. H. (2002). Commercial fertilizers: Their sources and use (4th ed.). Biotech Books.
Chicago Style (17th ed.) CitationCollings, Gilbeart H. Commercial Fertilizers: Their Sources and Use. 4th ed. Delhi: Biotech Books, 2002.
MLA (9th ed.) CitationCollings, Gilbeart H. Commercial Fertilizers: Their Sources and Use. 4th ed. Biotech Books, 2002.
Advarsel: Disse citationer er muligvist ikke 100% nøjagtige.