Perhaps you should try some spelling variations:
petroov » petrov (Expand Search), peteroov (Expand Search), petrooov (Expand Search), peroov (Expand Search)
petruv » petrov (Expand Search), peteruv (Expand Search), petrouv (Expand Search), peruv (Expand Search), pentruv (Expand Search)
petroow » petrow (Expand Search), peteroow (Expand Search), petrooow (Expand Search), peroow (Expand Search)
pero » petro (Expand Search), per (Expand Search), pro (Expand Search)
petr » peter (Expand Search), petro (Expand Search), per (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)

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 ((petroov OR petruv) OR (((petroow OR pero) OR perio) OR ((petr OR petru) OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroov OR petruv) OR (((petroow OR pero) OR perio) OR ((petr OR petru) OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petroov OR petruv) OR (((petroow OR pero) OR perio) OR ((petr OR petru) OR petri))) o.s.*.