APA (7th ed.) Citation

Hay, R. K. M., & Walker, A. J. (1989). An introduction to the physiology of crop yield / Robert K.M. Hay and Andrew J. Walker. Longman Scientific and Technical.

Chicago Style (17th ed.) Citation

Hay, R. K. M., and Andrew J. Walker. An Introduction to the Physiology of Crop Yield / Robert K.M. Hay and Andrew J. Walker. London: Longman Scientific and Technical, 1989.

MLA (9th ed.) Citation

Hay, R. K. M., and Andrew J. Walker. An Introduction to the Physiology of Crop Yield / Robert K.M. Hay and Andrew J. Walker. Longman Scientific and Technical, 1989.

Warning: These citations may not always be 100% accurate.