Perhaps you should try some spelling variations:
petrw » petrow (Expand Search), petru (Expand Search), petro (Expand Search), peterw (Expand Search), petruw (Expand Search)
peterow » petrow (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petrui » peterui (Expand Search), petruui (Expand Search), petroui (Expand Search), petru (Expand Search)
petroui » peteroui (Expand Search), petruoui (Expand Search), petrooui (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((((petrw OR peterow) OR peterow) o) OR (((petr OR petri) OR (petrui OR petroui)) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petrw OR peterow) OR peterow) o) OR (((petr OR petri) OR (petrui OR petroui)) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petrw OR peterow) OR peterow) o) OR (((petr OR petri) OR (petrui OR petroui)) _)). s.*.