@article{04159449, title = {Remarks on quadratic equations in Banach space.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {13}, year = {1990}, pages = {611-616}, doi = {10.1155/S0161171290000850}, zbl = {0706.47003}, language = {en}, url = {http://dml.mathdoc.fr/item/04159449} }
Argyros, Ioannis K. Remarks on quadratic equations in Banach space.. International Journal of Mathematics and Mathematical Sciences, Tome 13 (1990) pp. 611-616. doi : 10.1155/S0161171290000850. http://gdmltest.u-ga.fr/item/04159449/