APA (7th ed.) Citation

Collings, G. H. (1938). Commercial fertilizers: Their sources & use (2d ed.). P. Blakiston's Son & Co., inc..

Chicago Style (17th ed.) Citation

Collings, Gilbeart H. Commercial Fertilizers: Their Sources & Use. 2d ed. Philadelphia: P. Blakiston's Son & Co., inc., 1938.

MLA (9th ed.) Citation

Collings, Gilbeart H. Commercial Fertilizers: Their Sources & Use. 2d ed. P. Blakiston's Son & Co., inc., 1938.