Perhaps you should try some spelling variations:
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petruiiv (Expand Search)
petriuv » peteriuv (Expand Search), petriiuv (Expand Search), petruiuv (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petruou » peteruou (Expand Search), petriuou (Expand Search), petruuou (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 petriiv) OR (peteruv OR petriuv)) OR petruov) OR (petruou OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriiov OR petriiv) OR (peteruv OR petriuv)) OR petruov) OR (petruou OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriiov OR petriiv) OR (peteruv OR petriuv)) OR petruov) OR (petruou OR petr)) o.s.*.