Perhaps you should try some spelling variations:
petrov » petro (Expand Search), peterov (Expand Search), petroov (Expand Search), perov (Expand Search)
peterv » peter (Expand Search)
peters » peter (Expand Search), petersen (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (Expand Search)
petroov » peteroov (Expand Search), petrooov (Expand Search), peroov (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search), pentru (Expand Search)
petri » peteri (Expand Search), 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 ((((petrov OR (peterv OR peters)) OR petr) OR (petroov OR peroov)) OR (petru OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petrov OR (peterv OR peters)) OR petr) OR (petroov OR peroov)) OR (petru OR petri)) o.s.*".