Cita APA (7th ed.)

Burbidge, N., Gray, P., & Levy, S. Letters (2a ed.).

Cita Chicago (17th ed.)

Burbidge, Nicky, Peta Gray, i Sheila Levy. Letters. 2a ed.

Cita MLA (8th ed.)

Burbidge, Nicky, et al. Letters. 2a ed.