Cita APA (7th ed.)

DUFF, G. (1967). Partial differential equations. University of Toronto Press.

Cita Chicago (17th ed.)

DUFF, G.F.D. Partial Differential Equations. Toronto: University of Toronto Press, 1967.

Cita MLA (9th ed.)

DUFF, G.F.D. Partial Differential Equations. University of Toronto Press, 1967.