found: His quia natura nichil privatum, 1986:title page (Jan Hallebeek) page 175 (b. Utrecht 3-5-1954)
found: Schuld en boete, 1998:title page (J. Hallebeek)
found: KB internet search 12-20-99(Hallebeek, J. J.; full name: Johannes J. Hallebeek, born 1954; variant: Jan Hallebeek)
found: Quia natura nichil privatum, 1986 :thesis title page (Johannes Hallebeek) curriculum vitae (born in Utrecht, March 5, 1954)
found: Catalogus Professorum Academiae Rheno-Traiectinae, viewed October 19, 2022(J. Hallebeek ; born Utrecht, March 5th, 1954 ; professor of Old Catholic Church structures, including the history and teachings of the Old Catholic churches, 1997-2006; professor of history and doctrines of the Old Catholic churches, 1999-2016 ; since 1999 professor of legal history at the VU Amsterdam ; variant name: Joseph Hallebeek) - https://profs.library.uu.nl/index.php/profrec/getprofdata/782/39/127/0
