Passage: Alexander Alexandrovich Friedmann (also spelled Friedman or Fridman ; Russian: Алекса́ндр Алекса́ндрович Фри́дман) (June 16 [O.S. 4], 1888 – September 16, 1925) was a Russian and Soviet physicist and mathematician. He is best known for his pioneering theory that the universe was expanding, governed by a set of equations he developed now known as the Friedmann equations.

Question: What are two other ways Friedmann can be spelled?
Friedman or Fridman