Apostolic Constitution Universi Dominci Gregis ["The Shepherd of the Lord's whole flock'], Pope John Paul II, given February 26, 1996 [outlining and updating procedures to be followed after the death of a pope and in the election of a successor]. Excerpt:
The Shepherd of the Lord's whole flock is the Bishop of the Church of Rome, where the Blessed Apostle Peter, by sovereign disposition of divine Providence, offered to Christ the supreme witness of martyrdom by the shedding of his blood. It is therefore understandable that the lawful apostolic succession in this See, with which "because of its great pre-eminence every Church must agree", has always been the object of particular attention.
Precisely for this reason, down the centuries the Supreme Pontiffs have deemed it their special duty, as well as their specific right, to establish fitting norms to regulate the orderly election of their Successor.
Read the full text in English. Reported in JURIST's Paper Chase here.