Tikhonov, A. N., & Samarskií, A. A. (1963). Equations of mathematical physics. Pergamon Press.

Tikhonov, Andréi Nikolaevich, and Aleksandr Andreevich Samarskií. Equations of Mathematical Physics. Nueva York: Pergamon Press, 1963.

Tikhonov, Andréi Nikolaevich, and Aleksandr Andreevich Samarskií. Equations of Mathematical Physics. Pergamon Press, 1963.