David Widder
David Vernon Widder (25 March 1898 – 8 July 1990) was an American mathematician. He earned his Ph.D. at Harvard University in 1924 under George Birkhoff and went on to join the faculty there.He was a co-founder of the ''Duke Mathematical Journal'' and the author of the textbook ''Advanced Calculus'' (Prentice-Hall, 1947). He wrote also '' The Laplace transform'' (in which he gave a first solution to Landau's problem on the Dirichlet eta function), ''An introduction to transform theory'', and '' The convolution transform'' (co-author with I. I. Hirschman). Provided by Wikipedia