Jirapan Sonchaeng และ Viimollchaya Yanasugondha. (2008) Satisfaction of Thai members with Royal Orchid Plus (ROP) of Thai Airways International Public Company Limited (2007). Thammasat University:ม.ป.ท.Jirapan Sonchaeng และ Viimollchaya Yanasugondha. 2008. Satisfaction of Thai members with Royal Orchid Plus (ROP) of Thai Airways International Public Company Limited (2007). ม.ป.ท.:Thammasat University;Jirapan Sonchaeng และ Viimollchaya Yanasugondha. Satisfaction of Thai members with Royal Orchid Plus (ROP) of Thai Airways International Public Company Limited (2007). ม.ป.ท.:Thammasat University, 2008. Print.