Lersuk Hturpuch. 2527. "The main reason causing the problem of toxic substances." Technical training courses for the use of toxic agricultural safety of the 2nd Division of Agricultural Toxic Substances. Department of Agriculture, Ministry of Agriculture.
เลอศักดิ์. The จตุรภุช. 2527. "Causes the problem of toxic."). Academic papers, training course using toxic agricultural safely. The 2 division, Department of agriculture, the Ministry of agriculture agricultural toxic. .