Perhaps you should try some spelling variations:
petriw » petri (Expand Search), petris (Expand Search), petrow (Expand Search), peteriw (Expand Search), petriiw (Expand Search), petruiw (Expand Search)
petriov » petrov (Expand Search), peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petrou » petru (Expand Search), petro (Expand Search), petrov (Expand Search), peterou (Expand Search), petriou (Expand Search), petruou (Expand Search)
petero » peter (Expand Search), peters (Expand Search), petro (Expand Search)
petruiw » peteruiw (Expand Search), petriuiw (Expand Search), petruuiw (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petruiiv (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 ((((petriw OR petruiw) OR (petriov OR (petrou OR petero))) o) OR ((petr OR petriiv) _)). s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriw OR petruiw) OR (petriov OR (petrou OR petero))) o) OR ((petr OR petriiv) _)). s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriw OR petruiw) OR (petriov OR (petrou OR petero))) o) OR ((petr OR petriiv) _)). s.*.