@article{MZ_1972__129_171814,
     author = {Albert Wilansky and Andrew K. Snyder},
     title = {Non-Replaceable {Matrices.}},
     journal = {Mathematische Zeitschrift},
     pages = {21--24},
     publisher = {mathdoc},
     volume = {129},
     year = {1972},
     zbl = {0239.40004},
     url = {http://geodesic.mathdoc.fr/item/MZ_1972__129_171814/}
}