@article{AMLG_1975__17_137901,
     author = {Donald A. Alton},
     title = {Embedding relations in the lattice of recursively enumerable sets.},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {37--42},
     year = {1975},
     volume = {17},
     zbl = {0315.02040},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1975__17_137901/}
}