Reginald De Koven[?]
Rudolf Friml[?]
Victor Herbert
Emmerich Kalman[?], also known as Imre Kálmán
Franz Lehar
Jacques Offenbach
Sigmund Romberg[?]
Johann Strauss II
Arthur S. Sullivan (of Gilbert and Sullivan)
... and its proof remain correct if the coefficients a, b and c are complex numbers, or more generally members of any field whose characteristic is not 2. (In a field of ...