Zakhar’yashchev, M. V. Modal companions of superintuitionistic logics: Syntax, semantics, and preservation theorems. (English. Russian original) Zbl 0709.03017 Math. USSR, Sb. 68, No. 1, 277-289 (1990); translation from Mat. Sb. 180, No. 10, 1415-1427 (1989). MSC: 03B45 03B55 PDFBibTeX XMLCite \textit{M. V. Zakhar'yashchev}, Math. USSR, Sb. 68, No. 1, 277--289 (1990; Zbl 0709.03017); translation from Mat. Sb. 180, No. 10, 1415--1427 (1989) Full Text: DOI
Stepanov, V. I. On the theory of models for intuitionistic logic. (English. Russian original) Zbl 0568.03018 Math. USSR, Sb. 48, 223-235 (1984); translation from Mat. Sb., Nov. Ser. 120(162), No. 2, 227-239 (1983). MSC: 03C95 03F55 03C20 03C35 03B15 03B55 PDFBibTeX XMLCite \textit{V. I. Stepanov}, Math. USSR, Sb. 48, 223--235 (1984; Zbl 0568.03018); translation from Mat. Sb., Nov. Ser. 120(162), No. 2, 227--239 (1983) Full Text: DOI