Forbes D. Lewis. The Enumerability and Invariance of Complexity Classes. J. Comput. Syst. Sci., 5(3):286-303, 1971.
@article{Lewis71,
title = {The Enumerability and Invariance of Complexity Classes},
author = {Forbes D. Lewis},
year = {1971},
researchr = {https://researchr.org/publication/Lewis71},
cites = {0},
citedby = {0},
journal = {J. Comput. Syst. Sci.},
volume = {5},
number = {3},
pages = {286-303},
}