@article{SM_2011_202_9_a1,
     author = {A. N. Gorbachev and A. M. Stepin},
     title = {On the structure of invariant measures for set-valued maps},
     journal = {Sbornik. Mathematics},
     pages = {1285--1302},
     year = {2011},
     volume = {202},
     number = {9},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2011_202_9_a1/}
}