9. There are separate editions of some of the treatises of St. Ambrose, as of the Hexaëmeron and De Officiis Clericorum, in the Bibliotheca Patrum Eccl. Latinæ Selecta, Leipzig, Tauchnitz. The De Officiis has also been edited, with considerable improvements in the text, by Krabinger, Tübingen, 1857, and the De Fide and De Pœnitentia, by Hurter in the Vienna selections from the Fathers.