@other{https://resolver.caltech.edu/CaltechETD:etd-12062006-150937,
    title = "Studies in the flow of granular materials",
    year = "1980",
    url = "https://resolver.caltech.edu/CaltechETD:etd-12062006-150937",
    id = "record",
    doi = "10.7907/dm6x-9s32"
}