APA (7th ed.) Citation

Sawyers, J., & Williams, L. F. (1989). Difficult problems in general surgery. Year Book Medical Publishers.

Chicago Style (17th ed.) Citation

Sawyers, John, and Lester F. Williams. Difficult Problems in General Surgery. Chicago: Year Book Medical Publishers, 1989.

MLA (8th ed.) Citation

Sawyers, John, and Lester F. Williams. Difficult Problems in General Surgery. Year Book Medical Publishers, 1989.

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