Yanxi Liu, Robin J. Popplestone. A Group Theoretic Formalization of Surface Contact. I. J. Robotic Res., 13(2):148-161, 1994.
@article{LiuP94, title = {A Group Theoretic Formalization of Surface Contact}, author = {Yanxi Liu and Robin J. Popplestone}, year = {1994}, researchr = {https://researchr.org/publication/LiuP94}, cites = {0}, citedby = {0}, journal = {I. J. Robotic Res.}, volume = {13}, number = {2}, pages = {148-161}, }