Cita APA (7a ed.)

Dennis, N. (1994). Airline hub operations in Europe. [s.n.].

Cita Chicago Style (17a ed.)

Dennis, Nigel. Airline Hub Operations in Europe. [S.l.]: [s.n.], 1994.

Cita MLA (9a ed.)

Dennis, Nigel. Airline Hub Operations in Europe. [s.n.], 1994.