In 1911, Rayleigh complemented Ritz for his method for solving Chladni's problem, but complained for the lack of citation of his earlier work. However the similarity between Rayleigh's and Ritz's method has sometimes been challenged. Ritz's methods are sometimes referred as Rayleigh–Ritz method or simply Ritz method, depending on the procedure. Ritz's method led to the development of finite element method for the numerical solution of partial differential equations in physics.