Variations of Zorn's lemma, principles of cofinality, and Hausdorff's maximal principle. I. Set forms. - Judith M. Harper; Jean E. Rubin (Notre Dame J. Formal Log., 1976)

Variations of Zorn's lemma, principles of cofinality, and Hausdorff's maximal principle. II. Class forms. - Judith M. Harper; Jean E. Rubin (Notre Dame J. Formal Log., 1977)