@article{COCV_2007__13_4_657_0,
     author = {Wolansky, Gershon},
     title = {On the mobility and efficiency of mechanical systems},
     journal = {ESAIM: Control, Optimisation and Calculus of Variations},
     pages = {657--668},
     publisher = {EDP-Sciences},
     volume = {13},
     number = {4},
     year = {2007},
     doi = {10.1051/cocv:2007034},
     mrnumber = {2351396},
     zbl = {1123.37027},
     language = {en},
     url = {http://archive.numdam.org/articles/10.1051/cocv:2007034/}
}