Nguonsong Eung และ Kasem Choocharukul. (2015) TRAVEL BEHAVIOR AND FACTORS INFLUENCING FREQUENCY OF USING INFORMAL TRANSPORT AND PUBLIC BUS IN URBAN AREA OF PHNOM PENH. Chulalongkorn University:ม.ป.ท.Nguonsong Eung และ Kasem Choocharukul. 2015. TRAVEL BEHAVIOR AND FACTORS INFLUENCING FREQUENCY OF USING INFORMAL TRANSPORT AND PUBLIC BUS IN URBAN AREA OF PHNOM PENH. ม.ป.ท.:Chulalongkorn University;Nguonsong Eung และ Kasem Choocharukul. TRAVEL BEHAVIOR AND FACTORS INFLUENCING FREQUENCY OF USING INFORMAL TRANSPORT AND PUBLIC BUS IN URBAN AREA OF PHNOM PENH. ม.ป.ท.:Chulalongkorn University, 2015. Print.