van der Pol, Balth.; Bremmer, H. Modern operational calculus based on the two-sided Laplace integral. II. (English) Zbl 0039.32902 Proc. Akad. Wet. Amsterdam 51, 1125-1136 (1948). PDF BibTeX XML Cite \textit{Balth. van der Pol} and \textit{H. Bremmer}, Proc. Akad. Wet. Amsterdam 51, 1125--1136 (1948; Zbl 0039.32902)
van der Pol, Balth.; Bremmer, H. Modern operational calculus based on the two sided Laplace integral. I. (English) Zbl 0039.32901 Proc. Akad. Wet. Amsterdam 51, 1005-1012 (1948). PDF BibTeX XML Cite \textit{Balth. van der Pol} and \textit{H. Bremmer}, Proc. Akad. Wet. Amsterdam 51, 1005--1012 (1948; Zbl 0039.32901)