@article{COMIM_1998_6_1_a15,
     author = {Korec, Ivan},
     title = {Definability of arithmetical operations from binary quadratic forms},
     journal = {Communications in Mathematics},
     pages = {135--144},
     year = {1998},
     volume = {6},
     number = {1},
     mrnumber = {1822523},
     zbl = {1024.03011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/COMIM_1998_6_1_a15/}
}