Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruov » peteruov (Expand Search), petriuov (Expand Search), petruuov (Expand Search)
petruv » peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petriiuv » peteriiuv (Expand Search), petriiiuv (Expand Search), petruiiuv (Expand Search)
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petruiiv (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 ((((petriov OR petruov) OR (petruv OR petriiuv)) OR petriiv) OR petr) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriov OR petruov) OR (petruv OR petriiuv)) OR petriiv) OR petr) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriov OR petruov) OR (petruv OR petriiuv)) OR petriiv) OR petr) o.s.*.