@article{GDZPPN001265512, title = {On the closure of B2 ( ...,...).}, journal = {Semigroup forum}, volume = {54}, year = {1997}, pages = {166-174}, zbl = {0864.22001}, url = {http://dml.mathdoc.fr/item/GDZPPN001265512} }
Korkmaz, R. On the closure of B2 ( ...,...).. Semigroup forum, Tome 54 (1997) pp. 166-174. http://gdmltest.u-ga.fr/item/GDZPPN001265512/