Derrick, W. R., & Grossman, S. I. (1981). Elementary differential equations with applications (2d ed.). Addison-Wesley Pub. Co..

Derrick, William R., and Stanley I. Grossman. Elementary Differential Equations with Applications. 2d ed. Reading, Mass.: Addison-Wesley Pub. Co., 1981.

Derrick, William R., and Stanley I. Grossman. Elementary Differential Equations with Applications. 2d ed. Addison-Wesley Pub. Co., 1981.