@article{GDZPPN001258842, title = {Normal forms for band free products.}, journal = {Semigroup forum}, volume = {33}, year = {1986}, pages = {265-278}, zbl = {0615.20040}, url = {http://dml.mathdoc.fr/item/GDZPPN001258842} }
Olin, P. Normal forms for band free products.. Semigroup forum, Tome 33 (1986) pp. 265-278. http://gdmltest.u-ga.fr/item/GDZPPN001258842/