@article{CC_2007_36_4_a2,
     author = {Grzybowski, J. and Pallaschke, D. and Urba\'nski, R.},
     title = {Generalized directional derivatives for locally {Lipschitz} functions which satisfy {Leibniz} rule},
     journal = {Control and Cybernetics},
     pages = {911--924},
     publisher = {mathdoc},
     volume = {36},
     number = {4},
     year = {2007},
     zbl = {1234.26069},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CC_2007_36_4_a2/}
}