1. Wiener, N.: Nonlinear problems in random theory, (Chapman & Hall 1958)
2. Volterra, V.: Theory of functionals and of integral and integro-differential equations, (Blackie 1930)
3. ‘Measurement of the kernels of a nonlinear system by crosscorrelation’, Massachusetts Institute of Technology Research Laboratory of Electronics quarterly progress report, 60, 1961
4. ‘Measurement of a second-degree Wiener kernel in a nonlinear system by crosscorrelation’, Massachusetts Institute of Technology Research Laboratory of Electronics quarterly progress report, 65, 1962