@article{DMDICO_2001_21_2_a4,
     author = {Pastor, Karel},
     title = {On relations among the generalized second-order directional derivatives},
     journal = {Discussiones Mathematicae. Differential Inclusions, Control and Optimization},
     pages = {235--247},
     year = {2001},
     volume = {21},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMDICO_2001_21_2_a4/}
}