S. Barry Cooper. Jump Equivalence of the triangle :::0:::::2:: Hyperhyperimmune Sets. Journal of Symbolic Logic, 37(3):598-600, 1972.
@article{Cooper72, title = {Jump Equivalence of the triangle :::0:::::2:: Hyperhyperimmune Sets}, author = {S. Barry Cooper}, year = {1972}, researchr = {https://researchr.org/publication/Cooper72}, cites = {0}, citedby = {0}, journal = {Journal of Symbolic Logic}, volume = {37}, number = {3}, pages = {598-600}, }