Παραπομπή APA

Knowler, F., & Watkin, J. (1960). Practical Course in Agricultural Chemistry (2.). Macmillan and Company Ltd.

Παραπομπή Chicago Style

Knowler, Frank, και J.Elphin Watkin. Practical Course in Agricultural Chemistry. 2. London: Macmillan and Company Ltd, 1960.

Παραπομπή MLA

Knowler, Frank, και J.Elphin Watkin. Practical Course in Agricultural Chemistry. 2. Macmillan and Company Ltd, 1960.