@Article{Ram30,
    Author       = "Ramsey, F.P.",
    Year         = "1930",
    Title        = "{On a Problem of Formal Logic}",
    Journal      = "Proceedings of the London Mathematical Society",
    Number       = "30",
    Pages        = "264-286",
    DOI          = "{10.1112/plms/s2-30.1.264}",
    Comment      = "TPTPRef"
}