@other{https://resolver.caltech.edu/CaltechETD:etd-10192005-142203,
    title = "An experimental and theoretical study of the ECR plasma engine",
    year = "1993",
    url = "https://resolver.caltech.edu/CaltechETD:etd-10192005-142203",
    id = "record",
    doi = "10.7907/PDWR-J354"
}