Cita APA (7a ed.)

Thorburn, S., & Littlejohn, G. (1993). Underpinning and retention. Blackie Academic & Professional.

Cita Chicago Style (17a ed.)

Thorburn, S., y G.S Littlejohn. Underpinning and Retention. London [etc.]: Blackie Academic & Professional, 1993.

Cita MLA (9a ed.)

Thorburn, S., y G.S Littlejohn. Underpinning and Retention. Blackie Academic & Professional, 1993.