@other{https://resolver.caltech.edu/CaltechTHESIS:09152015-094552278,
    title = "Response of linear, viscous damped systems to excitations having time-varying frequency",
    year = "1966",
    url = "https://resolver.caltech.edu/CaltechTHESIS:09152015-094552278",
    id = "record",
    doi = "10.7907/NR49-C405"
}