APA (7th ed.) Citation

Lanczos, C. (1986). The variational principles of mechanics / by Cornelius Lanczos (4th ed.). Dover Publications.

Chicago Style (17th ed.) Citation

Lanczos, Cornelius. The Variational Principles of Mechanics / by Cornelius Lanczos. 4th ed. New York: Dover Publications, 1986.

MLA (9th ed.) Citation

Lanczos, Cornelius. The Variational Principles of Mechanics / by Cornelius Lanczos. 4th ed. Dover Publications, 1986.

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