Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
petro » petrov (Expand Search), petri (Expand Search), petru (Expand Search), petero (Expand Search), petrio (Expand Search), petruo (Expand Search)
petruuov » petrov (Expand Search), peteruuov (Expand Search), petriuuov (Expand Search), petruuuov (Expand Search)
petriuov » petrov (Expand Search), peteriuov (Expand Search), petriiuov (Expand Search), petruiuov (Expand Search)
petruv » peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petruiui » peteruiui (Expand Search), petriuiui (Expand Search), petruuiui (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 ((petriiov OR petruv) OR (((petro OR petruiui) OR (petruuov OR petriuov)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiov OR petruv) OR (((petro OR petruiui) OR (petruuov OR petriuov)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiov OR petruv) OR (((petro OR petruiui) OR (petruuov OR petriuov)) OR petr)) o.s.*.