Sugerencias
Quizá quiso decir:
Zill, Dennis G., 1940- Differential equations with modeling applications. Spanish
Symposium on Numerical Solution of Partial Differential Equations (1965 may 3-8 : Maryland)
Symposium on Asymptotic Solutions of Differential Equations and their Applications (1964 may 4-6 : Madison)
International Symposium on Nonlinear Differential Equations and Nonlinear Mechanics 1961 Colorado
International Symposium on Differential Equations and Dynamical Systems 1965 Puerto Rico
The Czechoslovak Conference on Differential Equations and their Applications 1962 Prague