@article{MM2_1992__75_4_155734,
     author = {Jie Du},
     title = {Integral schur algebras for {GL2.}},
     journal = {Manuscripta mathematica},
     pages = {411--428},
     publisher = {mathdoc},
     volume = {75},
     number = {4},
     year = {1992},
     zbl = {0767.20015},
     url = {http://geodesic.mathdoc.fr/item/MM2_1992__75_4_155734/}
}