Annetta, L. A., Folta, E., & Klesath, M. (2010). V-Learning: Distance Education in the 21st Century Through 3D Virtual Learning Environments. Springer Netherlands. https://doi.org/10.1007/978-90-481-3627-8

Annetta, Leonard A., Elizabeth Folta, and Marta Klesath. V-Learning: Distance Education in the 21st Century Through 3D Virtual Learning Environments. Dordrecht: Springer Netherlands, 2010. https://doi.org/10.1007/978-90-481-3627-8.

Annetta, Leonard A., et al. V-Learning: Distance Education in the 21st Century Through 3D Virtual Learning Environments. Springer Netherlands, 2010. https://doi.org/10.1007/978-90-481-3627-8.