Kanjana Sommit. 2002. Development of English lessons for improving listening and speaking skills of hotel service personnel through task-based learning activities. Field of Study Teaching English as a Foreign Language, Payap University;

Kanjana Sommit. Development of English lessons for improving listening and speaking skills of hotel service personnel through task-based learning activities. . Chiang Mai:Payap University, 2002.

Kanjana Sommit. (2002) Development of English lessons for improving listening and speaking skills of hotel service personnel through task-based learning activities . Payap University/Chiang Mai.