Perhaps you should try some spelling variations:
petrov » peterov (Expand Search), petroov (Expand Search), perov (Expand Search)
petruv » peteruv (Expand Search), petrouv (Expand Search), peruv (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (Expand Search)
petroio » peteroio (Expand Search), petrooio (Expand Search), peroio (Expand Search)
petruuo » peteruuo (Expand Search), petrouuo (Expand Search), peruuo (Expand Search)
petr » peter (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 (((petrov OR peterov) OR petruv) OR ((((petru OR petri) OR petroio) OR petruuo) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petrov OR peterov) OR petruv) OR ((((petru OR petri) OR petroio) OR petruuo) OR petr)) o.s.*".