TY  - RPRT
TI  - Virtual trackballs revisited.
AU  - Knud Henriksen
AU  - Jon Sporring
AU  - Kasper Hornbaek
DO  - 10.1109/tvcg.2004.1260772
UR  - https://pubmed.ncbi.nlm.nih.gov/15384645/
ID  - 15384645
ER  -