@article{AM2_1972__8_136297,
     author = {Jennifer Wallis},
     title = {On {Supplementary} {Difference} {Sets.}},
     journal = {Aequationes mathematicae},
     pages = {242--257},
     publisher = {mathdoc},
     volume = {8},
     year = {1972},
     zbl = {0255.05005},
     url = {http://geodesic.mathdoc.fr/item/AM2_1972__8_136297/}
}