1. Booton's problem re-examined;Elishakoff;J. Sound and Vibration,1998
2. R.C. Booton Jr., The analysis of non-linear control systems with random inputs, in: Proceedings of the Symposium on Nonlinear Circuit Analysis, Polytechnic Institute of Brooklyn, 1953, pp. 369–397; More easily obtained is: R.C. Booton, Jr., Nonlinear control systems with random inputs, IEEE Trans. Circuit Theory CT-1 (1954) 9–18.
3. Response of a non-linear string to random loading;Caughey;J. Appl. Mech.,1959
4. Equivalent linearization techniques;Caughey;J. Acoust. Soc. Amer.,1963
5. I.E. Kazakov, An approximate method for the statistical investigation of nonlinear systems, Trudi Voenna-Vozdushnoi Inzheneroi Akademii imeni Professora N.E. Zhukovskogo, Vol. 394, 1954 pp. 1–52 (in Russian); More easily obtained is: I.E. Kazakov, Approximate probabilistic analysis of the accuracy of operation of essentially nonlinear systems, Avtomatika I Telemekhanika 17 (1956) 385–409 (in Russian). (Which is available in Engl. transl.: Automat. Remote Control 17 (1956) 423–450).