@article{GDZPPN00241449X, title = {Combinatorial Structures in Loops.}, journal = {Mathematische Zeitschrift}, volume = {136}, year = {1974}, pages = {1-14}, zbl = {0276.05019}, url = {http://dml.mathdoc.fr/item/GDZPPN00241449X} }
Johnsen, Eugene C.; Storer, Thomas. Combinatorial Structures in Loops.. Mathematische Zeitschrift, Tome 136 (1974) pp. 1-14. http://gdmltest.u-ga.fr/item/GDZPPN00241449X/