@article{MZ_1991__208_3_174312,
     author = {Claus Michael Ringel},
     title = {The category of modules with good filtrations over a quasi-hereditary algebra has almost split sequences.},
     journal = {Mathematische Zeitschrift},
     pages = {209--224},
     publisher = {mathdoc},
     volume = {208},
     number = {3},
     year = {1991},
     zbl = {0725.16011},
     url = {http://geodesic.mathdoc.fr/item/MZ_1991__208_3_174312/}
}