Sources
http://wik.ed.uiuc.edu/index.php/Dreikurs%2C_Rudolf
http://ourworld.compuserve.com/homepages/hstein/guid.htm
http://cesp.utoledo.edu/mritchie/Courses/cmhs7530/unit_4/unit_4.htm
http://encarta.msn.com/encyclopedia_761566845/Alfred_Adler.html
http://adlereducation.com/
http://www.adleriansociety.co.uk/phdi/p3.nsf/supppages/0939?opendocument&part=7