en

http://easyworldofenglish.com

http://www.talkenglish.com/extralessons/speakingrules.aspx

http://1.lopngoaingu.com
http://vi.speaklanguages.com

http://www.dynamicbusinessplan.com/defaultvi.asp

http://hoctienganhhieuqua01.blogspot.com/2015/05/5-kenh-tren-youtube-hay-nhat-giup-ban.html

------------------------
http://ai2.appinventor.mit.edu/?locale=en

http://appinventor.mit.edu/explore/get-started.html

https://nguoithanhmien.blogspot.com/p/cung-hoc-app-inventor-2.html