@article{https://resolver.caltech.edu/CaltechAUTHORS:TSOjam65, title = "Parametric Excitation of a Nonlinear System", journal = "Journal of Applied Mechanics", year = "1965", url = "https://resolver.caltech.edu/CaltechAUTHORS:TSOjam65", id = "record", issn = "0021-8936", volume = "32" }