Joseph Y. Halpern, Moshe Y. Vardi. The Complexity of Reasoning about Knowledge and Time. I. Lower Bounds. J. Comput. Syst. Sci., 38(1):195-237, 1989.
@article{HalpernV89, title = {The Complexity of Reasoning about Knowledge and Time. I. Lower Bounds}, author = {Joseph Y. Halpern and Moshe Y. Vardi}, year = {1989}, researchr = {https://researchr.org/publication/HalpernV89}, cites = {0}, citedby = {0}, journal = {J. Comput. Syst. Sci.}, volume = {38}, number = {1}, pages = {195-237}, }