@other{https://resolver.caltech.edu/CaltechETD:etd-11112004-104123,
    title = "Vibration of granular materials",
    year = "1997",
    url = "https://resolver.caltech.edu/CaltechETD:etd-11112004-104123",
    id = "record",
    doi = "10.7907/QMSQ-QJ88"
}