บรรณานุกรม
http://www.school.net.th/library/webcontest2003/100team/dlnes141/t5/t5_9.html http://www.maceducation.com/e-knowledge/2422210100/14.htm
http://www.school.net.th/library/webcontest2003/100team/dlnes141/t5/t5_9.html
http://www.maceducation.com/e-knowledge/2422210100/14.htm