@article{PORMA_1997__54_3_47865,
     author = {Queir\'o, Jo\~ao Filipe},
     title = {Axioms for invariant factors.},
     journal = {Portugaliae mathematica},
     pages = {263--269},
     publisher = {mathdoc},
     volume = {54},
     number = {3},
     year = {1997},
     zbl = {0887.15003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1997__54_3_47865/}
}