@article{ZNSL_2012_405_a1,
     author = {Yu. A. Al'pin and V. S. Al'pina},
     title = {Combinatorial properties of irreducible semigroups of nonnegative matrices},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {13--23},
     publisher = {mathdoc},
     volume = {405},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2012_405_a1/}
}