Pichai Suvanprapaporn. 1991. Study and analysis of the salt efforesence production process in the Northeastern Thailand : a case study of Ban Muang district and Wanon Niwat district, Sakon Nakhon Province. Faculty of Graduate Studies, Mahidol University;
Pichai Suvanprapaporn. (1991) Study and analysis of the salt efforesence production process in the Northeastern Thailand : a case study of Ban Muang district and Wanon Niwat district, Sakon Nakhon Province . Mahidol University/Bangkok.
Pichai Suvanprapaporn. Study and analysis of the salt efforesence production process in the Northeastern Thailand : a case study of Ban Muang district and Wanon Niwat district, Sakon Nakhon Province. . Bangkok:Mahidol University, 1991.
Pichai Suvanprapaporn. (1991) Study and analysis of the salt efforesence production process in the Northeastern Thailand : a case study of Ban Muang district and Wanon Niwat district, Sakon Nakhon Province . Mahidol University/Bangkok.