Permitting, Forcing, and Copying of a Given Recursive Relation

@article{Ash1997PermittingFA,
  title={Permitting, Forcing, and Copying of a Given Recursive Relation},
  author={Christopher J. Ash and Peter Cholak and Julia F. Knight},
  journal={Ann. Pure Appl. Logic},
  year={1997},
  volume={86},
  pages={219-236}
}