Snedecor, G. W., & Cochran, W. G. (1956). Statistical methods: Applied to experiments in agriculture and biology (5a. ed.). The Iowa State University Press.

Snedecor, George Waddel, and William Gemmell Cochran. Statistical Methods: Applied to Experiments in Agriculture and Biology. 5a. ed. Ames: The Iowa State University Press, 1956.

Snedecor, George Waddel, and William Gemmell Cochran. Statistical Methods: Applied to Experiments in Agriculture and Biology. 5a. ed. The Iowa State University Press, 1956.