Erratum: The Correlation between Effective Factors of E-learning and Demographic Variables in a Post-Graduate Program of Virtual Medical Education in Tehran University of Medical Sciences - Golband, Farnoosh; Hosseini, Agha Fatemeh; Mojtahedzadeh, Rita; Mirhosseini, Fakhrossadat; Bigdeli, Shoaleh (Acta Medica Iranica)