@other{https://resolver.caltech.edu/CaltechETD:etd-01152008-082733,
    title = "Differentially flat nonlinear control systems",
    year = "1997",
    url = "https://resolver.caltech.edu/CaltechETD:etd-01152008-082733",
    id = "record",
    doi = "10.7907/k7pm-hs13"
}