@article{https://resolver.caltech.edu/CaltechAUTHORS:FEYpr54b,
    title = "Proton-neutron mass difference",
    journal = "Physical Review",
    url = "https://resolver.caltech.edu/CaltechAUTHORS:FEYpr54b",
    id = "record",
    issn = "0031-899X",
    doi = "10.1103/PhysRev.94.500",
    volume = "94"
}