Dionisio, John David n.; Burns III, William G.; Gilbert, Richard. 3D Virtual Worlds and the Metaverse: Current Status and Future Possibilities. ACM Computing Surveys (ACM). 2013, 45 (3): 34:1 – 34:38. S2CID 12667518. doi:10.1145/2480741.2480751.
Dionisio, John David n.; Burns III, William G.; Gilbert, Richard. 3D Virtual Worlds and the Metaverse: Current Status and Future Possibilities. ACM Computing Surveys (ACM). 2013, 45 (3): 34:1 – 34:38. S2CID 12667518. doi:10.1145/2480741.2480751.