@other{https://resolver.caltech.edu/CaltechTHESIS:10202017-140716441,
    title = "Optimal Filtering for Systems Governed by Coupled Ordinary and Partial Differential Equations",
    year = "1973",
    url = "https://resolver.caltech.edu/CaltechTHESIS:10202017-140716441",
    id = "record",
    doi = "10.7907/C7W5-8C39"
}