APA (7th ed.) Citation

Willems, N., Easley, J. T., & Rolfe, S. T. (1981). Strength of materials. McGraw-Hill.

Chicago Style (17th ed.) Citation

Willems, Nicholas, John T. Easley, and S. T. Rolfe. Strength of Materials. New York: McGraw-Hill, 1981.

MLA (9th ed.) Citation

Willems, Nicholas, et al. Strength of Materials. McGraw-Hill, 1981.