@article{1183741695,
author = {Welch, Lawrence V.},
title = {A Hierarchy of Families of Recursively Enumerable Degrees},
journal = {J. Symbolic Logic},
volume = {49},
number = {1},
year = {1984},
pages = { 1160-1170},
language = {en},
url = {http://dml.mathdoc.fr/item/1183741695}
}
Welch, Lawrence V. A Hierarchy of Families of Recursively Enumerable Degrees. J. Symbolic Logic, Tome 49 (1984) no. 1, pp. 1160-1170. http://gdmltest.u-ga.fr/item/1183741695/