1. Allen, I. E. & Seaman, J. (2010). Learning on demand: Online education in the United States, 2009. Sloan-C. http://sloanconsortium.org/publications/survey/pdf/learningondemand.pdf
2. Allen, I. E. & Seaman, J. (2013). Changing course: Ten years of tracking online education in the United States (No. ED541571). Sloan Consortium. http://sloanconsortium.org/publications/survey/changing_course_2012
3. Impacts of an online-supported, resource-based learning environment: does one size fit all?