Journal article reprint from: Journal of the American Society of Agronomy, v.28:no.12 (1936:Dec.).
Serial issue. Issued as: West Virginia University. Agricultural Experiment Station. Mimeograph circular, no. 60 (1949:Feb.).
Serial issue. Issued as: West Virginia University. Agricultural Experiment Station. Mimeograph circular, no. 64 (1950:Feb.).