His first work, "Alcune difficoltà principali della grammatica" (Ancona, 1637), dealing with
Latin grammar, was written while he was engaged in teaching the humanities. He devoted his later years to the study of history and bibliography. He prepared a new annotated edition of the "History of the
Popes" by
Alphonsus Ciacconius, up to
Clement IX (1667-9), "Vitæ et res gestæ Pontificum Romanorum et S.R.E. Cardinalium Alphonsi Ciacconi, O.P." (4 volumes, Rome, 1670–77). In connection with this he also published the following: "Necrologium Pontificum ac Pseudo-Pontificum Romanorum" (Rome, 1671); "Clementes titulo sanctitatis vel morum sanctimonia illustres" (Perugia, 1675); "Athenæum Romanum, in quo Summorum Pontificum ac Pseudo-Pontificum necnon S.R.E. Cardinalium et Pseudo-Cardinalium scripta publice exponuntur" (Perugia, 1670).
J. Meuschen published an excerpt from Oldoini's "Catalogus eorum qui de Romanis Pontificibus scripserunt", in his work "Ceremonialia electionis Pontificum Romanorum" (Frankfort, 1731). Oldoini also published "Athenæum Augustum, in quo Perusinorum scripta publice exponuntur" (Perugia, 1680) and "Athenæum Ligusticum seu Syllabus Scriptorum Ligurum necnon Sarzanensium ac Cyrnensium rei publicæ Genuensis Subditorum" (Perugia, 1680). ==References==