Perhaps you should try some spelling variations:
petrov » peterov (Expand Search), perov (Expand Search)
petr » peter (Expand Search), per (Expand Search)
petrowi » peterowi (Expand Search), perowi (Expand Search), petrow (Expand Search), petrowna (Expand Search)
petro » petero (Expand Search), pero (Expand Search)
petru » peteru (Expand Search), peru (Expand Search), pentru (Expand Search)
petrou » peterou (Expand Search), perou (Expand Search), petrow (Expand Search)
petri » peteri (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 ((petrov OR perov) OR (petr OR (((petrowi OR petro) OR (petru OR petrou)) OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petrov OR perov) OR (petr OR (((petrowi OR petro) OR (petru OR petrou)) OR petri))) o.s.*".