@article{SM_1990_66_1_a16,
     author = {A. L. Yakymiv},
     title = {On the number of $A$-permutations},
     journal = {Sbornik. Mathematics},
     pages = {301--311},
     year = {1990},
     volume = {66},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1990_66_1_a16/}
}