Richard S. Westfall  is best known for his biography of a mathematician who was a key figure in what?
Richard S. Westfall Richard S. Westfall (April 22, 1924 – August 21, 1996) was an American academic, biographer and historian of science. He is best known for his biography of Isaac Newton and his work on the scientific revolution of the 17th century.
Richard S. Varga Richard Steven Varga ( ; born October 9, 1928) is an American mathematician who specializes in numerical analysis and linear algebra. He is currently an Emeritus University Professor of Mathematical Sciences at Kent State University and an adjunct Professor at Case Western Reserve University. Varga is known for his contributions to many areas of mathematics, including matrix analysis, complex analysis, approximation theory, and scientific computation. He is the author of the classic textbook "Matrix Iterative Analysis". Varga has been the Editor-in-Chief of the journal "Electronic Transactions on Numerical Analysis" (ETNA).