Opera Omnia, Leonine Edition (1882-)
This Leonine Edition of Opera Omnia is the standard critical edition.  The definitive text of Aquinas's writings is being published by the Leonine Comission, established by Pope Leo XIII in 1880.  Pope Leo XIII entrusted the Dominican Order with the task of editing a critical edition of the works of St. Thomas Aquinas in Latin.  The work of the Leonine Comission is still unfinished.  The Corpus Thomisticum website presents the entirety of the works of St. Thomas Aquinas in Latin.  For the most updated list of works included in the Opera Omnia  click here.  The set is available in the Religious Studies and Philosophy Library Folios, room 316 (BQ 6822 1882).

Opera Omnia, reprint of Parma Edition (1852-1873)
This series is a reprint of the original Parma series from 1852-1873 and is considered one of the definitive Thomistic series the library possesses. Its twenty-five volumes aim to give you the complete works of St. Thomas in Latin. Its introduction (written in English) gives a chronology of Thomas's works, discusses the structure of his writings, lists printings done of complete works of Aquinas, looks at the life of Thomas, and gives a cursory glance at research done on Thomas Aquinas.  The set is available in the Religious Studies and Philosophy Library, room 314 (BQ 6822 1948).  The original set can be found in the Mullen library stacks folios (1 South, BQ 6822 1852)

Opera Omnia, Vives Edition (1871-1880)
This is a thirty-four volume set.  Each volume includes an index (Quaestionum et Articulorum) at the end of the book.  The last volume (v. 34) provides and index to the entire set.  This set is located in Stacks 3A Center, (BQ 6822 1871).      

Summa Theologiae (Blackfriars edition)
This sixty-one volume set contains Latin texts and English translation, introductions, notes, appendices, and glossaries.  Edited by Dominicans from English-speaking Provinces of the Order.  Includes bibliographical references [BQ 6838 .E5 1964].  

Summa Theologica (Benziger Bros. edition)
Literally translated by Fathers of the English Dominican Province.  Includes synoptical charts. 

How to Cite Summa Theologica?
Citing Summa Theologica is easy once you understand its structure. For more information click here.

Summa Contra Gentiles (Latin)
Editio Leonina manualis.  This work is available in the Religious Studies and Philosophy Library, room 314 (BQ6862 .A2 1934) 

Summa Contra Gentiles (English)
Translated by A. C. Pegis, J. F. Anderson, V. J. Bourke, and C. J. O’Neil.  This work is available in the Religious Studies and Philosophy Library, room 314 (BQ 6862 .A3 E5 1975).  Reprint of the same edition is published by Hanover House, Garden City, N.Y., under title: "On the Truth of the Catholic Faith".  This work is also available online: Book 1, Book 2, Book 3 pt. 1, Book 3 pt.2, Book 4.