@article{CM_1956-1958__13__81_0,
     author = {Tarski, Alfred and Vaught, Robert L.},
     title = {Arithmetical extensions of relational systems},
     journal = {Compositio Mathematica},
     pages = {81--102},
     publisher = {Kraus Reprint},
     volume = {13},
     year = {1956-1958},
     mrnumber = {95121},
     zbl = {0091.01201},
     language = {en},
     url = {http://www.numdam.org/item/CM_1956-1958__13__81_0/}
}