TY - BOOK AU - International Symposium, United States Air Force Academy, Colarado, 31 July - 4 August, 1961 AU - LaSalle, Joseph P., ed. AU - Lefschetz, Solomon., ed. TI - Non-linear differential equations and nonlinear mechanics - Proceedings U1 - 515.35 PY - 1963/// CY - New York PB - Academic Press ER -