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)
... 2, the element 2a is zero and it is impossible to divide by it.) The symbol <math>\pm \sqrt {b^2-4ac}</math> in the formula should be understood ...