Cita APA (7a ed.)

Walker, E., & Elsworth, S. (1991). Blueprint: Workbook: intermediate. Longman Longman Group UK Limited.

Cita Chicago Style (17a ed.)

Walker, Elaine, y Steve Elsworth. Blueprint: Workbook: Intermediate. Essex, Inglaterra: Longman Longman Group UK Limited, 1991.

Cita MLA (9a ed.)

Walker, Elaine, y Steve Elsworth. Blueprint: Workbook: Intermediate. Longman Longman Group UK Limited, 1991.