Perhaps you should try some spelling variations:
perov » petrov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petrooi (Expand Search)
petrioi » peterioi (Expand Search), petriioi (Expand Search), petroioi (Expand Search)
petriioi » peteriioi (Expand Search), petriiioi (Expand Search), petroiioi (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petriu » peteriu (Expand Search), petriiu (Expand Search), petroiu (Expand Search)
petriou » peteriou (Expand Search), petriiou (Expand Search), petroiou (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (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 (perov OR (((petroi OR (petrioi OR petriioi)) OR ((petru OR petriu) OR petriou)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (perov OR (((petroi OR (petrioi OR petriioi)) OR ((petru OR petriu) OR petriou)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (perov OR (((petroi OR (petrioi OR petriioi)) OR ((petru OR petriu) OR petriou)) OR petr)) o.s.*.