Ratchumas Lappayawichit. 1998. An investigation of English language learning strategies and their relation to the achievement of the first-year arts students at Chulalongkorn University. Faculty of Graduate Studies, Mahidol University;

Ratchumas Lappayawichit. An investigation of English language learning strategies and their relation to the achievement of the first-year arts students at Chulalongkorn University. . Bangkok:Mahidol University, 1998.

Ratchumas Lappayawichit. (1998) An investigation of English language learning strategies and their relation to the achievement of the first-year arts students at Chulalongkorn University . Mahidol University/Bangkok.