@article{SMJ2_2004_30_4_a6,
     author = {Khoury, Joseph},
     title = {A {Note} on {Elementary} {Derivations}},
     journal = {Serdica Mathematical Journal},
     pages = {549--570},
     year = {2004},
     volume = {30},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SMJ2_2004_30_4_a6/}
}