Prince Charles and Lady Diana's wedding anniversary was a traditional wedding service.
Jan Arnoldus Schouten -LRB- 28 August 1883 -- 20 January 1971 -RRB- was a Dutch mathematician and Professor at the Delft University of Technology .. Dutch. Netherlands. Delft University of Technology. Delft University of Technology. mathematician. mathematician. He was an important contributor to the development of tensor calculus and Ricci calculus , and was one of the founders of the Mathematisch Centrum in Amsterdam .. tensor calculus. tensor calculus. Ricci calculus. Ricci calculus. Mathematisch Centrum. Centrum Wiskunde & Informatica. Amsterdam. Amsterdam