Burke, K., & Brooks, J. (1999). Wavelength: Elementary coursebook. Pearson Education.
Citazione stile Chigago Style (17a edizione)Burke, Kathy, e Julia Brooks. Wavelength: Elementary Coursebook. Essex: Pearson Education, 1999.
Citatione MLA (9a ed.)Burke, Kathy, e Julia Brooks. Wavelength: Elementary Coursebook. Pearson Education, 1999.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.