Cita APA (7a ed.)

Willis, J. R., & Willis, D. (1996). Challenge and change in language teaching. MacMillan Heineman English Language Teaching.

Cita Chicago Style (17a ed.)

Willis, Jane R., y Dave Willis. Challenge and Change in Language Teaching. Oxford: MacMillan Heineman English Language Teaching, 1996.

Cita MLA (9a ed.)

Willis, Jane R., y Dave Willis. Challenge and Change in Language Teaching. MacMillan Heineman English Language Teaching, 1996.