Further basic results were proved in the early 20th century. For example, the Riesz representation theorem was independently established by Maurice Fréchet and Frigyes Riesz in 1907.[14] John von Neumann coined the term abstract Hilbert space in his work on unbounded Hermitian operators.[15] Although other mathematicians such as Hermann Weyl and Norbert Wiener had already studied particular Hilbert spaces in great detail, often from a physically motivated point of view, von Neumann gave the first complete and axiomatic treatment of them.[16] Von Neumann later used them in his seminal work on the foundations of quantum mechanics,[17] and in his continued work with Eugene Wigner.