Cita APA (7th ed.)
Zill, D. G., & Cullen, M. R. (1997). Differential equations with boundary-value problems (4th ed.). Brooks/Cole Pub. Co..
Cita Chicago (17th ed.)
Zill, Dennis G., i Michael R. Cullen. Differential Equations with Boundary-value Problems. 4th ed. Pacific Grove: Brooks/Cole Pub. Co., 1997.
Cita MLA (9th ed.)
Zill, Dennis G., i Michael R. Cullen. Differential Equations with Boundary-value Problems. 4th ed. Brooks/Cole Pub. Co., 1997.
Atenció: Aquestes cites poden no estar 100% correctes.