Cita APA (7th ed.)

KELLS, L. M. (1960). Elementary differential equations. McGraw-Hill.

Cita Chicago (17th ed.)

KELLS, Lyman M. Elementary Differential Equations. New York: McGraw-Hill, 1960.

Cita MLA (9th ed.)

KELLS, Lyman M. Elementary Differential Equations. McGraw-Hill, 1960.