Perhaps you should try some spelling variations:
petrooi » petrovoi (Expand Search), petruoi (Expand Search), peterooi (Expand Search), petruooi (Expand Search), perooi (Expand Search)
petro » petrov (Expand Search), petru (Expand Search), petero (Expand Search), petruo (Expand Search), pero (Expand Search)
petruov » peteruov (Expand Search), petruuov (Expand Search), peruov (Expand Search)
petruou » peteruou (Expand Search), petruuou (Expand Search), peruou (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), peri (Expand Search)
petr » peter (Expand Search), petru (Expand Search), per (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 (((peterou OR petruou) OR (petri OR petrooi)) OR (petro OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petruov OR (((peterou OR petruou) OR (petri OR petrooi)) OR (petro OR petr))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petruov OR (((peterou OR petruou) OR (petri OR petrooi)) OR (petro OR petr))) o.s.*.