Name this fella
He was a mathematician and a leading book author on Mathematics. His books became the de facto standard textbook for Mathematics in most colleges and universities around the world.
He taught at Cal State L.A., Phoenix College in Arizona, the Open University of Great Britain, the University of Southern California and, most recently, Pepperdine University. In his 70s, he turned to teaching AP calculus in high schools.
He died on April 29, 2005 due to natural causes.
CLUE: He authored two books that are the standard Math textbooks in UP.
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