@inproceedings{usoh1999walkingenvironments,
 author = {Usoh M, Arthur K, Whitton MC, Bastos R, Steed A, Slater M, Brooks FP},
 title = {Walking > walking-in-place > flying, in virtual environments},
 year = {1999},
 booktitle = {Proceedings of the 26th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH 1999},
}