http://educationnext.hks.harvard.edu/the-detracking-movement/
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.421.139&rep=rep1&type=pdf
https://www.soe.vt.edu/highered/files/students/Sample2.pdf
http://ejournals.library.vanderbilt.edu/index.php/vurj/article/viewFile/3795/1880
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.421.139&rep=rep1&type=pdf
https://www.soe.vt.edu/highered/files/students/Sample2.pdf
http://ejournals.library.vanderbilt.edu/index.php/vurj/article/viewFile/3795/1880