Introduction to Christianity by Joseph Ratzinger (Pope Benedict XVI)

Catechism of the Catholic Church

Catholic Theology by James J. Buckley; Frederick C. Bauerschmidt

Systematic Theology: a Roman Catholic Approach by Thomas P. Rausch

Systematic Theology: Roman Catholic Perspectives by Francis Schussler Fiorenza (Editor); John P. Galvin (Editor)

Catholic Christianity by Peter Kreeft

Catholicism by Mario Farrugia; Gerald O'Collins

Catholicism by Richard P. McBrien

The Christian Faith in the Doctrinal Documents of the Catholic Church by Josef Neuner (Editor); J. Dupuis (Editor)

God Encountered: a Contemporary Catholic Systematic Theology by Frans J. Van Beeck