@article{10_4153_CMB_1969_011_x,
     author = {Bean, D. T.},
     title = {Solution to a {Matroid} {Problem} {Posed} by {D.} {J.} {A.} {Welsh}},
     journal = {Canadian mathematical bulletin},
     pages = {129--131},
     year = {1969},
     volume = {12},
     number = {2},
     doi = {10.4153/CMB-1969-011-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1969-011-x/}
}