Each congregation kept its own book of the dead, but not everywhere has survived to this day, and those we have differ in value. Among the obituaries written in Norbertine monasteries, the most valuable is the orbitary of the Abbey of St Wincenty near Wrocław - the only one in this group that has survived in its original form from the Middle Ages. All the rest are known only from late copies or redactions. A little-known source is the book of the dead of the Norbertine monastery in Zwierzyniec. The manuscript of the obituary comes from 1719 and is titled: "The List of Names of the Rest in God the Brothers, Sisters and Benefactors of All Monasteries of the Polish Premonstratum of the Deceased..." and was prepared by Józef Herman Zawarski, the vicar of Zwierzyniec. It is a paper codex, bound in leather, without decorations. It is kept in the monastery archive and contains 121 pages, numbered by Zawarski, with over 2,000 commemorative notes about people from the 12th to the beginning of the 18th century. The obituary of the monastery in Zwierzyniec is one of the few manuscripts of this congregation dating back to the early Middle Ages. It is one of the most valuable sources from Zwierzyniec, next to the 16th century copier and the books of the higher court of German law.