@article{JGG_2001_5_2_a1,
     author = {J. Lang and S. Mick and O. R�schel},
     title = {The {Rigidity} {Rate} of {Positions} of {Stewart-Gough} {Platforms}},
     journal = {Journal for geometry and graphics},
     pages = {121--132},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {2001},
     url = {http://geodesic.mathdoc.fr/item/JGG_2001_5_2_a1/}
}