@article{AMLG_1960__5_137758,
     author = {J.C. Shepherdson},
     title = {Representability of recursively enumerable sets in formal theories.},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {119--127},
     publisher = {mathdoc},
     volume = {5},
     year = {1960},
     zbl = {0113.24305},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1960__5_137758/}
}