@article{04030296, title = {M-quasi-hyponormal composition operators.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {10}, year = {1987}, pages = {621-623}, doi = {10.1155/S0161171287000760}, zbl = {0633.47013}, language = {en}, url = {http://dml.mathdoc.fr/item/04030296} }
Suri, Pushpa R.; Singh, N. M-quasi-hyponormal composition operators.. International Journal of Mathematics and Mathematical Sciences, Tome 10 (1987) pp. 621-623. doi : 10.1155/S0161171287000760. http://gdmltest.u-ga.fr/item/04030296/