Perhaps you should try some spelling variations:
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petruv » petru (Expand Search), petrov (Expand Search), petriuv (Expand Search), petruuv (Expand Search), petrouv (Expand Search)
petruuuiov » petriuuuiov (Expand Search), petruuuuiov (Expand Search), petrouuuiov (Expand Search)
petruou » petriuou (Expand Search), petruuou (Expand Search), petrouou (Expand Search)
petrouou » petriouou (Expand Search), petruouou (Expand Search), petroouou (Expand Search)
petr » petri (Expand Search), petru (Expand Search), petro (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 petruuuiov) OR ((petruou OR petrouou) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petriov OR petruv) OR petruuuiov) OR ((petruou OR petrouou) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petriov OR petruv) OR petruuuiov) OR ((petruou OR petrouou) OR (petr OR peter))) o.s.*.