Worakarn Singhato และ Ardiporn khemarangsan. (2010) Voluntourism : a model for the deveolpment of community based tourism activities in Northern Thailand. Silpakorn University:ม.ป.ท.Worakarn Singhato และ Ardiporn khemarangsan. 2010. Voluntourism : a model for the deveolpment of community based tourism activities in Northern Thailand. ม.ป.ท.:Silpakorn University;Worakarn Singhato และ Ardiporn khemarangsan. Voluntourism : a model for the deveolpment of community based tourism activities in Northern Thailand. ม.ป.ท.:Silpakorn University, 2010. Print.