Perhaps you should try some spelling variations:
petruov » petrov (Expand Search), petruuov (Expand Search), petrouov (Expand Search), peruov (Expand Search)
petroi » petro (Expand Search), petrov (Expand Search), petrow (Expand Search), petruoi (Expand Search), petrooi (Expand Search), peroi (Expand Search)
peters » petersen (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (Expand Search)
petroov » petruoov (Expand Search), petrooov (Expand Search), peroov (Expand Search), petrov (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 (petruov OR (((petroi OR petri) OR peters) OR ((petr OR petroov) OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petruov OR (((petroi OR petri) OR peters) OR ((petr OR petroov) OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petruov OR (((petroi OR petri) OR peters) OR ((petr OR petroov) OR peter))) o.s.*.