@article{MSH_1975__51__43_0,
     author = {Thomassen, Carsten},
     title = {Transversals of circuits in the lexicographic product of directed graphs},
     journal = {Math\'ematiques et sciences humaines},
     pages = {43--45},
     publisher = {Ecole Pratique des hautes \'etudes, Centre de math\'ematique sociale et de statistique},
     volume = {51},
     year = {1975},
     mrnumber = {392659},
     zbl = {0315.05109},
     language = {en},
     url = {http://www.numdam.org/item/MSH_1975__51__43_0/}
}