@other{https://resolver.caltech.edu/CaltechETD:etd-10232007-082738,
    title = "Dihydrofolate reductase gene amplification in human cell lines VA2-B and hela BU25",
    url = "https://resolver.caltech.edu/CaltechETD:etd-10232007-082738",
    id = "record",
    doi = "10.7907/pfsj-xf27"
}