Gaya APA

ZILL, D, G., CULLEN, M, R. (2009). Differential Equations: With Boundary-Value Problems 7ed (7). Belmont: Brooks/Cole Cengage Learning .

Gaya MLA

ZILL, Dennis, G.., CULLEN, Michael, R.. "Differential Equations: With Boundary-Value Problems 7ed". 7 Belmont: Brooks/Cole Cengage Learning , 2009. Printed.