Denis R. Hirschfeldt, Walker M. White. Realizing Levels of the Hyperarithmetic Hierarchy as Degree Spectra of Relations on Computable Structures. Notre Dame Journal of Formal Logic, 43(1):51-64, 2002.
@article{HirschfeldtW02,
title = {Realizing Levels of the Hyperarithmetic Hierarchy as Degree Spectra of Relations on Computable Structures},
author = {Denis R. Hirschfeldt and Walker M. White},
year = {2002},
researchr = {https://researchr.org/publication/HirschfeldtW02},
cites = {0},
citedby = {0},
journal = {Notre Dame Journal of Formal Logic},
volume = {43},
number = {1},
pages = {51-64},
}