@article{00039585, title = {Derived length for arbitrary topological spaces.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {15}, year = {1992}, pages = {273-277}, doi = {10.1155/S0161171292000358}, zbl = {0799.54003}, language = {en}, url = {http://dml.mathdoc.fr/item/00039585} }
Jayanthan, A.J. Derived length for arbitrary topological spaces.. International Journal of Mathematics and Mathematical Sciences, Tome 15 (1992) pp. 273-277. doi : 10.1155/S0161171292000358. http://gdmltest.u-ga.fr/item/00039585/