@article{https://resolver.caltech.edu/CaltechAUTHORS:20140408-091626297,
    title = "The Electron Polar Cap and the Boundary of the Open Geomagnetic Field Lines",
    journal = "Journal of Geophysical Research A",
    year = "1971",
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140408-091626297",
    id = "record",
    issn = "0148-0227",
    doi = "10.1029/JA077i028p05580",
    volume = "77"
}


@article{https://resolver.caltech.edu/CaltechAUTHORS:20140407-084852501,
    title = "Access of solar protons into the polar cap: A persistent north-south asymmetry",
    journal = "Journal of Geophysical Research A",
    year = "1969",
    url = "https://resolver.caltech.edu/CaltechAUTHORS:20140407-084852501",
    id = "record",
    issn = "0148-0227",
    doi = "10.1029/JA074i021p05127",
    volume = "74"
}