APA (7th ed.) Citation

Sagan, H. (1992). Introduction to the calculus of variations. Dover Publications.

Chicago Style (17th ed.) Citation

Sagan, Hans. Introduction to the Calculus of Variations. New York: Dover Publications, 1992.

MLA (9th ed.) Citation

Sagan, Hans. Introduction to the Calculus of Variations. Dover Publications, 1992.

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