Dardzhaniya, G. K. On the complexity of countermodels for intuitionistic propositional calculus. (Russian) Zbl 0417.03032 Soobshch Akad. Nauk Gruz. SSR 95, 17-20 (1979). MSC: 03F99 03B55 PDFBibTeX XMLCite \textit{G. K. Dardzhaniya}, Soobshch. Akad. Nauk Gruz. SSR 95, 17--20 (1979; Zbl 0417.03032)
Statman, Richard Intuitionistic propositional logic is polynomial-space complete. (English) Zbl 0411.03049 Theor. Comput. Sci. 9, 67-72 (1979). MSC: 03F20 03D15 03F55 03B40 PDFBibTeX XMLCite \textit{R. Statman}, Theor. Comput. Sci. 9, 67--72 (1979; Zbl 0411.03049) Full Text: DOI Link
Cook, Stephen A.; Reckhow, Robert A. The relative efficiency of propositional proof systems. (English) Zbl 0408.03044 J. Symb. Log. 44, 36-50 (1979). MSC: 03F20 03B05 PDFBibTeX XMLCite \textit{S. A. Cook} and \textit{R. A. Reckhow}, J. Symb. Log. 44, 36--50 (1979; Zbl 0408.03044) Full Text: DOI