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Sone Bhongaraya. (1998) Geomorphology of the ping and the Wang River Basin Amphoe Sam Ngao and Ban Tak area Changwat Tak . Chulalongkorn University/Bangkok.
Sone Bhongaraya. Geomorphology of the ping and the Wang River Basin Amphoe Sam Ngao and Ban Tak area Changwat Tak. . Bangkok:Chulalongkorn University, 1998.
Sone Bhongaraya. (1998) Geomorphology of the ping and the Wang River Basin Amphoe Sam Ngao and Ban Tak area Changwat Tak . Chulalongkorn University/Bangkok.