See this online ebook:
- Gregorian Reform of the Calendar: Proceedings of the Vatican Conference to commemorate its 400th Anniversary, 1582-1982: Extra Series 3, edited by G.V. Coyne, S.J., M.A. Hoskin, and O. Pedersen (Vatican City: Pontifical Academy of Sciences, Specola Vaticana, 1982). pp. xxv-323. Available in PDF format at the Pontifical Academy of Sciences.
On Leap Day 2016 in the Gregorian Calendar. For other legally free ebooks, you may access the List of Free eBooks (Arranged by Title) and the List of Free eBooks (Grouped by Subject).
O God, our refuge and our strength, look down with mercy upon the people who cry to Thee; and by the intercession of the glorious and immaculate Virgin Mary, Mother of God, of Saint Joseph her spouse, of the blessed Apostles Peter and Paul, and of all the saints, in Thy mercy and goodness hear our prayers for the conversion of sinners, and for the liberty and exaltation of the Holy Mother the Church. Through the same Christ Our Lord. Amen. (From Sancta Missa)