แหล่งอ้างอิง

 https://sites.google.com/site/madoobook/home/khwam-hmay-khxng-kar-xan

 http://www.st.ac.th/bhatips/tip49/reading1.html

 https://sites.google.com/site/phasathiykabkarchi/bth-thi-4-kar-subkhn-laea-karna-senx/3-3-prapheth-khxng-kar-xan

 https://www.gotoknow.org/posts/552299

https://www.gotoknow.org/posts/237840

 https://blog.eduzones.com/jybjub/12187

 https://sites.google.com/a/htp.ac.th/kar-xan-pheux-kar-wikheraah-wicarn/4-khan-txn-kar-wikheraah-wicarn

http://www.thaigoodview.com/library/teachershow/utaradit/kanjana-c/thailand01/sec02p05.html

https://blog.eduzones.com/GlobalAcademyLadphrao/141407