Aragon, S. R. (2003). Creating social presence in online environments. New Directions for Adult and Continuing Education, 100, 57-68.
Noseworthy, E., & Boswell, W. (2016). Supporting learners in the virtual classroom through instructor presence. In K. A. Flores, K. D. Kirstein, C. E. Schieber, & S. G. Olswang (Eds.), Supporting the success of adult and online students: Proven practices in higher education (5th ed., pp. 271–280). Seattle, WA: CreateSpace Independent.