@article{00650833, title = {Extremal problems for completely positive maps.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {17}, year = {1994}, pages = {607-608}, doi = {10.1155/S0161171294000852}, zbl = {0805.46058}, language = {en}, url = {http://dml.mathdoc.fr/item/00650833} }
Yang, Mingze. Extremal problems for completely positive maps.. International Journal of Mathematics and Mathematical Sciences, Tome 17 (1994) pp. 607-608. doi : 10.1155/S0161171294000852. http://gdmltest.u-ga.fr/item/00650833/