Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petruv » peteruv (Expand Search), petriuv (Expand Search), petruuv (Expand Search)
petriv » peteriv (Expand Search), petriiv (Expand Search), petruiv (Expand Search)
petriuv » peteriuv (Expand Search), petriiuv (Expand Search), petruiuv (Expand Search)
petruui » peteruui (Expand Search), petriuui (Expand Search), petruuui (Expand Search)
petriui » peteriui (Expand Search), petriiui (Expand Search), petruiui (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 (petruv OR petriv)) OR petriuv) OR ((petruui OR petriui) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR (petruv OR petriv)) OR petriuv) OR ((petruui OR petriui) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR (petruv OR petriv)) OR petriuv) OR ((petruui OR petriui) OR petr)) o.s.*.