@article{CC_2006_35_4_a5,
     author = {Girejko, Ewa and Bartosiewicz, Zbigniew},
     title = {Viability and generalized differential quotients},
     journal = {Control and Cybernetics},
     pages = {815--829},
     publisher = {mathdoc},
     volume = {35},
     number = {4},
     year = {2006},
     zbl = {1133.49019},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CC_2006_35_4_a5/}
}