The 1570 bull Quo primum of Pope Pius V in a Roman Missal. Below the name of the pope Pius Episcopus (Pius Bishop) appears his title Servus servorum Dei. Not all papal documents begin in this way, but bulls do.
Gabriel Adeleye, Kofi Acquah-Dadzie, Thomas J. Sienkewicz, World dictionary of foreign expressions: a resource for readers (1999) "Servus servorum Dei", p. 361.
Ian Robinson The papal reform of the eleventh century p326 - 2004 "Gregory bishop, servant of the servants of God, to the archbishops, bishops , dukes, counts and the greater and lesser men in the kingdom of the Germans, greeting and apostolic blessing."
