Perhaps you should try some spelling variations:
petroiuv » petrov (Expand Search), peteroiuv (Expand Search), petrioiuv (Expand Search), petruoiuv (Expand Search)
perov » petrov (Expand Search)
peri » petri (Expand Search), per (Expand Search)
peru » petru (Expand Search), per (Expand Search)
petruv » peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petriiu » peteriiu (Expand Search), petriiiu (Expand Search), petruiiu (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 ((petruv OR petroiuv) OR (((perov OR peri) OR ((petriiu OR peteru) OR peru)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR petroiuv) OR (((perov OR peri) OR ((petriiu OR peteru) OR peru)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruv OR petroiuv) OR (((perov OR peri) OR ((petriiu OR peteru) OR peru)) OR petr)) o.s.*.