APA (7th ed.) Citation

Harper, J. E., Schrader, L. E., Howell, R. W., & Hageman, R. H. (1985). Exploitation of physiological and genetic variability to enhance crop productivity. American Society of Plant Physiologists.

Chicago Style (17th ed.) Citation

Harper, James E., Lawrence E. Schrader, Robert W. Howell, and Richard Harry Hageman. Exploitation of Physiological and Genetic Variability to Enhance Crop Productivity. Rockville, Md.: American Society of Plant Physiologists, 1985.

MLA (9th ed.) Citation

Harper, James E., et al. Exploitation of Physiological and Genetic Variability to Enhance Crop Productivity. American Society of Plant Physiologists, 1985.