Sumana Poonphon. 2001. The consumption of environmental friendly products by femal instructors : a case study of Rajabhat Institute Phra Nakhon Sri Ayutthaya in Phra Nakhon Sri Ayutthaya province. Field of Study Technology of Environmental Planning for Rural Development, Mahidol University;
Sumana Poonphon. (2001) The consumption of environmental friendly products by femal instructors : a case study of Rajabhat Institute Phra Nakhon Sri Ayutthaya in Phra Nakhon Sri Ayutthaya province . Mahidol University/Bangkok.
Sumana Poonphon. The consumption of environmental friendly products by femal instructors : a case study of Rajabhat Institute Phra Nakhon Sri Ayutthaya in Phra Nakhon Sri Ayutthaya province. . Bangkok:Mahidol University, 2001.
Sumana Poonphon. (2001) The consumption of environmental friendly products by femal instructors : a case study of Rajabhat Institute Phra Nakhon Sri Ayutthaya in Phra Nakhon Sri Ayutthaya province . Mahidol University/Bangkok.