Cita APA (7a ed.)

Haines, S., & Brewster, S. (1992). Challenge upper intermediate students' book. T. Nelson.

Cita Chicago Style (17a ed.)

Haines, Simon, y Simon Brewster. Challenge Upper Intermediate Students' Book. Edinburgh: T. Nelson, 1992.

Cita MLA (8a ed.)

Haines, Simon, y Simon Brewster. Challenge Upper Intermediate Students' Book. T. Nelson, 1992.