@article{02220820, title = {Relative natural classes and relative injectivity.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {2005}, year = {2005}, pages = {671-678}, doi = {10.1155/IJMMS.2005.671}, zbl = {1085.16020}, language = {en}, url = {http://dml.mathdoc.fr/item/02220820} }
Crivei, Septimiu. Relative natural classes and relative injectivity.. International Journal of Mathematics and Mathematical Sciences, Tome 2005 (2005) pp. 671-678. doi : 10.1155/IJMMS.2005.671. http://gdmltest.u-ga.fr/item/02220820/