Keenan, S. (1876). A doctrinal catechism: Wherein divers points of Catholic faith and practice assailed by modern heretics are sustained by an appeal to the holy scriptures, the testimony of the ancient fathers, and the dictates of reason, on the basis of Scheffmacher's catechism (3rd Amer. ed., rev. and corr.). P.J. Kenedy.

Keenan, Stephen. A Doctrinal Catechism: Wherein Divers Points of Catholic Faith and Practice Assailed by Modern Heretics Are Sustained by an Appeal to the Holy Scriptures, the Testimony of the Ancient Fathers, and the Dictates of Reason, on the Basis of Scheffmacher's Catechism. 3rd Amer. ed., rev. and corr. New York: P.J. Kenedy, 1876.

Keenan, Stephen. A Doctrinal Catechism: Wherein Divers Points of Catholic Faith and Practice Assailed by Modern Heretics Are Sustained by an Appeal to the Holy Scriptures, the Testimony of the Ancient Fathers, and the Dictates of Reason, on the Basis of Scheffmacher's Catechism. 3rd Amer. ed., rev. and corr. P.J. Kenedy, 1876.