@article{JCA_2011_18_4_JCA_2011_18_4_a7,
     author = {E. Girejko and D. Mozyrska and M. Wyrwas},
     title = {Contingent {Epiderivatives} of {Functions} on {Time} {Scales}},
     journal = {Journal of convex analysis},
     pages = {1047--1064},
     publisher = {mathdoc},
     volume = {18},
     number = {4},
     year = {2011},
     url = {http://geodesic.mathdoc.fr/item/JCA_2011_18_4_JCA_2011_18_4_a7/}
}