Roman Catechism 33.61

Chapter 33 — Part IV: Prayer — On Prayer in General

Section 61. To The Saints — We must also have recourse to the intercession of the Saints who are in glory. That the Saints are to be prayed to is a truth so firmly established in the Church of God, that no pious person can experience a shadow of doubt on the subject. But as this point was explained in its proper place, under a separate head, we refer the pastor and others to that place.