APA
Ooi G. T., Institute of Southeast Asian Studies, . (1981). The ASEAN preferential trading arrangements (PTA). Singapore: Institute of Southeast Asian Studies.
Chicago
Ooi Guat Tin, Institute of Southeast Asian Studies, . 1981. The ASEAN preferential trading arrangements (PTA). Singapore: Institute of Southeast Asian Studies.
Harvard
Ooi G. T., Institute of Southeast Asian Studies, . (1981). The ASEAN preferential trading arrangements (PTA). Singapore: Institute of Southeast Asian Studies.
MLA
Ooi Guat Tin, Institute of Southeast Asian Studies, . The ASEAN preferential trading arrangements (PTA). Singapore: Institute of Southeast Asian Studies. 1981.
