@article{GDZPPN001253662, title = {The average rank of a product of transformations.}, journal = {Semigroup forum}, volume = {20}, year = {1980}, pages = {79-86}, zbl = {0429.20057}, url = {http://dml.mathdoc.fr/item/GDZPPN001253662} }
Roush, F.W.; Kim, K.H. The average rank of a product of transformations.. Semigroup forum, Tome 20 (1980) pp. 79-86. http://gdmltest.u-ga.fr/item/GDZPPN001253662/