Cita APA (7a ed.)

Grundy, J., Frau Walz, & Deissmann, G. Brush up your German. Linguaphone Institute.

Cita Chicago Style (17a ed.)

Grundy, J.B.C, Frau Walz, y G. Deissmann. Brush Up Your German. London: Linguaphone Institute.

Cita MLA (9a ed.)

Grundy, J.B.C, et al. Brush Up Your German. Linguaphone Institute.