@other{https://resolver.caltech.edu/CaltechETD:etd-09252002-110658,
    title = "Eigenvalue problems for positive monotonic nonlinear operators",
    year = "1968",
    url = "https://resolver.caltech.edu/CaltechETD:etd-09252002-110658",
    id = "record",
    doi = "10.7907/R8T3-TJ18"
}