Perko, L. (1991). Differential equations and dynamical systems. Springer-Verlag.
शिकागो स्टाइल उद्धरणPerko, Lawrence. Differential Equations and Dynamical Systems. New York: Springer-Verlag, 1991.
एमएलए उद्धरणPerko, Lawrence. Differential Equations and Dynamical Systems. Springer-Verlag, 1991.
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