Gaya APA

Keeffe, I, D, &, M, O. (2003). English for international tourism : Pre-intermediate students' book . England: Pearson Education Limited.

Gaya MLA

Keeffe, Iwonna, Dubicka, &, Margaret, O.. "English for international tourism : Pre-intermediate students' book". England: Pearson Education Limited, 2003. Electronic Resource.