Prompen Wattanbud. 2008. Attitudes towards the use of English of customer relations officers at the British Council (Thailand). Bangkok:Thammasat University; DOI : https://doi.nrct.go.th/ListDoi/listDetail?Resolve_DOI=10.14457/TU.the.2008.167
Prompen Wattanbud. (2008) Attitudes towards the use of English of customer relations officers at the British Council (Thailand) (รายงานผลงานวิจัย). Thammasat University:Bangkok. DOI : https://doi.nrct.go.th/ListDoi/listDetail?Resolve_DOI=10.14457/TU.the.2008.167
Prompen Wattanbud. Attitudes towards the use of English of customer relations officers at the British Council (Thailand). Bangkok:Thammasat University, 2008. DOI : https://doi.nrct.go.th/ListDoi/listDetail?Resolve_DOI=10.14457/TU.the.2008.167
Prompen Wattanbud. (2008) Attitudes towards the use of English of customer relations officers at the British Council (Thailand) (รายงานผลงานวิจัย). Thammasat University:Bangkok. DOI : https://doi.nrct.go.th/ListDoi/listDetail?Resolve_DOI=10.14457/TU.the.2008.167