N. Silachan, W. Pluemcharoen, P. Pichyapaiboon, and S. Sukarawan, “Development of a Workshop Curriculum on Environmental Education Project for Teachers of Schools Surrounding The Boundary of Dong-Yai Wildlife Sanctuary, Buri Ram Province”, kasetsart J. Soc. Sci., vol. 27, no. 2, pp. 163–174, Dec. 2006.