@article{10_4153_CJM_1969_145_0,
     author = {Welsh, D. J. A.},
     title = {Transversal {Theory} and {Matroids}},
     journal = {Canadian journal of mathematics},
     pages = {1323--1330},
     year = {1969},
     volume = {21},
     number = {1},
     doi = {10.4153/CJM-1969-145-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1969-145-0/}
}