On M. G. Krein's papers in the theory of spaces with an indefinite metric
This is a surv ey of the papers by M. G. Krein (and his disciples) devoted to the theory of operators in the spaces with indefinite metric and its applications.
English version (Springer): Ukrainian Mathematical Journal 46 (1994), no. 1-2, pp 3-14.
Citation Example: Azizov T. Ya., Ginsburg Yu. P., Langer H. On M. G. Krein's papers in the theory of spaces with an indefinite metric // Ukr. Mat. Zh. - 1994. - 46, № 1-2. - pp. 5–17.