@article{AM2_1996__52_1-2_137661,
     author = {Diane Donovan and Joan Cooper},
     title = {Critical sets in back circulant latin squares.},
     journal = {Aequationes mathematicae},
     pages = {157--179},
     publisher = {mathdoc},
     volume = {52},
     number = {1-2},
     year = {1996},
     zbl = {0859.05025},
     url = {http://geodesic.mathdoc.fr/item/AM2_1996__52_1-2_137661/}
}