Majorizing provably recursive functions in fragments of PA. Andrea Cantini (1985) Archiv für mathematische Logik und Grundlagenforschung
Modal Translations of Heyting and Peano Arithmetic Kosta Došen (1990) Publications de l'Institut Mathématique
More on extending automorphisms of models of Peano Arithmetic Roman Kossak, Henryk Kotlarski (2008) Fundamenta Mathematicae Continuing the earlier research [Fund. Math. 129 (1988) and 149 (1996)] we give some information about extending automorphisms of models of PA to cofinal extensions.