Theodore P. Baker, Alan L. Selman. A Second Step Toward the Polynomial Hierarchy. Theoretical Computer Science, 8:177-187, 1979.
@article{BakerS79, title = {A Second Step Toward the Polynomial Hierarchy}, author = {Theodore P. Baker and Alan L. Selman}, year = {1979}, researchr = {https://researchr.org/publication/BakerS79}, cites = {0}, citedby = {0}, journal = {Theoretical Computer Science}, volume = {8}, pages = {177-187}, }