APA (7th ed.) Citation

Giacaglia, G. E. O. (1972). Pertubation methods in non linear systems. Springer.

Chicago Style (17th ed.) Citation

Giacaglia, G. E. O. Pertubation Methods in Non Linear Systems. New York: Springer, 1972.

MLA (9th ed.) Citation

Giacaglia, G. E. O. Pertubation Methods in Non Linear Systems. Springer, 1972.