@article{DCG_1989__4_6_131093,
     author = {L.J. Guibas and Sharir Micha and Shmuel Sifrony},
     title = {On the {General} {Motion-Planning} {Problem} with {Two} {Degrees} of {Freedom.}},
     journal = {Discrete & computational geometry},
     pages = {491--522},
     publisher = {mathdoc},
     volume = {4},
     number = {6},
     year = {1989},
     zbl = {0685.68049},
     url = {http://geodesic.mathdoc.fr/item/DCG_1989__4_6_131093/}
}