Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petru » pentru (Expand Search), petri (Expand Search), petriu (Expand Search), petrou (Expand Search), peru (Expand Search)
petroov » petrov (Expand Search), petrioov (Expand Search), petrooov (Expand Search), peroov (Expand Search)
petria » petri (Expand Search), petra (Expand Search), petriia (Expand Search), petroia (Expand Search), peria (Expand Search)
petris » petri (Expand Search), petriis (Expand Search), petrois (Expand Search), peris (Expand Search)
petriou » petriiou (Expand Search), petroiou (Expand Search), periou (Expand Search)
petr » petri (Expand Search), petro (Expand Search), per (Expand Search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((petriov OR (((petru OR petroov) OR petria) OR petris)) OR (petriou OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR (((petru OR petroov) OR petria) OR petris)) OR (petriou OR (petr OR peter))) o.s.*".