1. Isomorphic recursive structures;Ash,1998
2. Permitting, forcing, and copying of a given recursive relation;Ash;Ann. Pure Appl. Logic,1997
3. Intrinsically recursive relations;Ash,1981
4. Intrinsically Σα0 relations;Barker;Ann. Pure Appl. Logic,1988
5. Computably categorical structures and expansions by constants;Cholak;J. Symbolic Logic,1999