@misc {IOPORT.70374476,
    author       = {Sinnet, Ryan W. and Ames, Aaron D.},
    title        = {3D bipedal walking with knees and feet: A hybrid geometric approach},
    howpublished = {CDC, 3208-3213 (2009).},
    year         = {2009},
    doi          = {10.1109/CDC.2009.5400457},
    identifier   = {70374476},
}