Askerov, N. K.; Krein, S. G.; Laptev, G. I. Oscillations of a viscous liquid and the associated operational equations. (Russian) Zbl 0186.21104 Funkts. Anal. Prilozh. 2, No. 2, 21-31 (1968). PDFBibTeX XMLCite \textit{N. K. Askerov} et al., Funkts. Anal. Prilozh. 2, No. 2, 21--31 (1968; Zbl 0186.21104)
Krein, S. G.; Laptev, G. I. Motion of a viscous liquid in an open vessel. (Russian) Zbl 0175.11002 Funkts. Anal. Prilozh. 2, No. 1, 40-50 (1968). PDFBibTeX XMLCite \textit{S. G. Krein} and \textit{G. I. Laptev}, Funkts. Anal. Prilozh. 2, No. 1, 40--50 (1968; Zbl 0175.11002)