Stephen A. Fenner, Lance Fortnow, Lide Li. Gap-Definability as a Closure Property. Inf. Comput., 130(1):1-17, 1996.
@article{FennerFL96, title = {Gap-Definability as a Closure Property}, author = {Stephen A. Fenner and Lance Fortnow and Lide Li}, year = {1996}, researchr = {https://researchr.org/publication/FennerFL96}, cites = {0}, citedby = {0}, journal = {Inf. Comput.}, volume = {130}, number = {1}, pages = {1-17}, }