Birkhoff, G., & Rota, G. (1978). Ordinary differential equations (3rd ed.). Wiley.

Birkhoff, Garrett, and Gian-Carlo Rota. Ordinary Differential Equations. 3rd ed. New York: Wiley, 1978.

Birkhoff, Garrett, and Gian-Carlo Rota. Ordinary Differential Equations. 3rd ed. Wiley, 1978.