@Article{Cha70,
    Author       = "Chang, C-L.",
    Year         = "1970",
    Title        = "{The Unit Proof and the Input Proof in Theorem Proving}",
    Journal      = "Journal of the ACM",
    Volume       = "17",
    Number       = "4",
    Pages        = "698-707",
    Comment      = "TPTPRef, resolution/linear systems"
}