DUACASTELLA L.A., El Cardenal John Henry Newman:el principio de participación como fundamento de una filosofía cristiana: su relación con los Padres de la Iglesia.
Leonardo da Vinci, Roma 2002, 189 pp.
Dissertation, Duquesne University 2001, 329 pp.
Dissertation, Washington, D.C. 2001, 263 p.
Union Theological Seminary, New York City 2001, 258 p.
Baylor University, Waco TX, 2001, 340 p.
Teachers College, Columbia University, 2001, 419 p.
A critical Evaluation of the Universal Call to Holiness in the Life and Writings of John Henry Cardinal Newman, Pontificia Studiorum Universitas a S. Thoma Aquino in Urbe, Roma 2001, 139 pp.
A Perspective from which to view the Contemporary Discussion regarding the Marian Titles of Co-Redemptrix, Mediatrix and Advocate, Pontificia Facultas Marianum, Roma 2001, 603 pp. Published in 2004. See below.
Pontificia Studiorum Universitas a S. Thoma Aquino in Urbe, Roma 2001, VI + pp.102.
Pontificia Universitas Gregoriana, Roma 2001, 249 pp.