@article{AL_1972_11_2_a7,
     author = {A. H. Lachlan},
     title = {Two theorems on many-one degrees of recursively enumerable sets},
     journal = {Algebra i logika},
     pages = {216--229},
     publisher = {mathdoc},
     volume = {11},
     number = {2},
     year = {1972},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AL_1972_11_2_a7/}
}