@other{https://resolver.caltech.edu/CaltechEERL:1964.EERL.1964.003,
    title = "Vibration of viscously damped linear dynamic systems",
    year = "1964",
    url = "https://resolver.caltech.edu/CaltechEERL:1964.EERL.1964.003",
    id = "record"
}


@other{https://resolver.caltech.edu/CaltechEERL:1963.DYNL-63-01,
    title = "General theory of vibration of damped linear dynamic systems",
    year = "1963",
    url = "https://resolver.caltech.edu/CaltechEERL:1963.DYNL-63-01",
    id = "record"
}


@other{https://resolver.caltech.edu/CaltechEERL:1961.DYNL.1961.001,
    title = "Normal modes in damped systems",
    year = "1961",
    url = "https://resolver.caltech.edu/CaltechEERL:1961.DYNL.1961.001",
    id = "record"
}