Perhaps you should try some spelling variations:
petris » petrois (Expand Search), peris (Expand Search)
petr » petro (Expand Search), per (Expand Search)
petru » petrou (Expand Search), peru (Expand Search), pentru (Expand Search)
petrooi » petroooi (Expand Search), perooi (Expand Search)
petroov » petrooov (Expand Search), peroov (Expand Search), petrov (Expand Search)
petriu » petroiu (Expand Search), periu (Expand Search)
petri » petroi (Expand Search), peri (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 ((petris OR (petr OR petru)) OR (((petrooi OR petroov) OR petriu) OR (petri OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petris OR (petr OR petru)) OR (((petrooi OR petroov) OR petriu) OR (petri OR peter))) o.s.*".