@article{PORMA_1997__54_3_47853,
     author = {Sommen, F.},
     title = {An algebra of abstract vector variables.},
     journal = {Portugaliae mathematica},
     pages = {287--310},
     publisher = {mathdoc},
     volume = {54},
     number = {3},
     year = {1997},
     zbl = {0886.15037},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1997__54_3_47853/}
}