TY  - BOOK
AU  - Downey
TI  - A Hierarchy of Turing Degrees: A Transfinite Hierarchy of Lowness Notions in the Computably Enumerable Degrees, Unifying Classes, and Natural Definability (AMS-206)
PB  - IEEE
UR  - https://ieeexplore.ieee.org/servlet/opac?bknumber=9452519
ER  -