@article{GDZPPN002233223, title = {Integral schur algebras for GL2.}, journal = {Manuscripta mathematica}, volume = {76}, year = {1992}, pages = {411-428}, zbl = {0767.20015}, url = {http://dml.mathdoc.fr/item/GDZPPN002233223} }
Du, Jie. Integral schur algebras for GL2.. Manuscripta mathematica, Tome 76 (1992) pp. 411-428. http://gdmltest.u-ga.fr/item/GDZPPN002233223/