@article{MZ_1968__105_170978,
     author = {M.S. Macphail and S.C. Chang and A. Snyder},
     title = {Constency and {Replaceability} for {Conull} {Matrices.}},
     journal = {Mathematische Zeitschrift},
     pages = {208--212},
     publisher = {mathdoc},
     volume = {105},
     year = {1968},
     zbl = {0155.38801},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__105_170978/}
}