 On Non-Linear Differential Equations of the Second Order, Part I by Mary Cartwright and John Edensor Littlewood

Journal of the London Mathematical Society s1-20(3), 180–189, June 1945. Publisher title continues with the forced van der Pol equation and large-parameter qualification. Original publisher byline is M. L. Cartwright and J. E. Littlewood. Cited for the joint investigation of forced nonlinear oscillations; no unsupported priority claim for chaos theory.