Rod Downey, Carl G. Jockusch Jr., Timothy H. McNicholl, Paul E. Schupp. Asymptotic density and the Ershov hierarchy. Math. Log. Q., 61(3):189-195, 2015. [doi]
@article{DowneyJMS15,
title = {Asymptotic density and the Ershov hierarchy},
author = {Rod Downey and Carl G. Jockusch Jr. and Timothy H. McNicholl and Paul E. Schupp},
year = {2015},
doi = {10.1002/malq.201300081},
url = {http://dx.doi.org/10.1002/malq.201300081},
researchr = {https://researchr.org/publication/DowneyJMS15},
cites = {0},
citedby = {0},
journal = {Math. Log. Q.},
volume = {61},
number = {3},
pages = {189-195},
}