@article{CMUC_1987_28_1_a18,
     author = {Jir\'asek, Jozef},
     title = {On a certain class of multidigraphs, for which reversal of no arc decreases the number of their cycles},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {185--189},
     year = {1987},
     volume = {28},
     number = {1},
     mrnumber = {889780},
     zbl = {0624.05034},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1987_28_1_a18/}
}