Krasovskij, N. N.; Sobolev, S. L.; Tikhonov, A. N. Valentin Konstantinovich Ivanov (on his seventieth birthday). (English) Zbl 0429.01011 Russ. Math. Surv. 34, No. 2, 261-267 (1979). MSC: 01A70 PDFBibTeX XMLCite \textit{N. N. Krasovskij} et al., Russ. Math. Surv. 34, No. 2, 261--267 (1979; Zbl 0429.01011) Full Text: DOI
Krasovskij, N. N.; Sobolev, S. L.; Tikhonov, A. N. Valentin Konstantinovic Ivanov (Zum siebzigsten Geburtstag). (Russian) Zbl 0401.01012 Usp. Mat. Nauk 34, No. 2(206), 229-234 (1979). MSC: 01A70 PDFBibTeX XMLCite \textit{N. N. Krasovskij} et al., Usp. Mat. Nauk 34, No. 2(206), 229--234 (1979; Zbl 0401.01012)
Oleĭnik, O. A.; Sobolev, S. L.; Tikhonov, A. N. The works of I. G. Petrovskiĭ on partial differential equations and their role in the development of the theory of differential equations. (Russian) Zbl 0493.01021 Partial differential equations, Proc. All-Union Conf., Moscow 1976, dedic. I. G. Petrovskij, 9-20 (1978). MSC: 01A60 35-03 PDFBibTeX XML
Sobolev, S. L.; Tikhonov, A. N.; Erugin, N. P. Men of Soviet science: on the 50th birthday of A. V. Bitsadze. (English) Zbl 0176.27103 Differ. Equ. 2 (1966), 373-375 (1969). MSC: 01A70 PDFBibTeX XMLCite \textit{S. L. Sobolev} et al., Differ. Uravn. 2, 716--719 (1966; Zbl 0176.27103)
Sobolev, S. L.; Tikhonov, A. N.; Erugin, N. P. Zum 50. Geburtstag von A. V. Bitsadze. (Russian) Zbl 0156.24706 Differ. Uravn. 2, 716-719 (1966). PDFBibTeX XMLCite \textit{S. L. Sobolev} et al., Differ. Uravn. 2, 716--719 (1966; Zbl 0156.24706)