Sudsuang Yutdhana. 2000. A survey of English language needs of businesspersons in Chiang Mai. , Naresuan University;
Sudsuang Yutdhana. (2000) A survey of English language needs of businesspersons in Chiang Mai . Naresuan University/Phitsanulok.
Sudsuang Yutdhana. A survey of English language needs of businesspersons in Chiang Mai. . Phitsanulok:Naresuan University, 2000.
Sudsuang Yutdhana. (2000) A survey of English language needs of businesspersons in Chiang Mai . Naresuan University/Phitsanulok.