Perhaps you should try some spelling variations:
petroi » petri (Expand Search), petro (Expand Search), petrov (Expand Search), petrioi (Expand Search), petruoi (Expand Search), petrooi (Expand Search)
petriov » petrov (Expand Search), petriiov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petruov » petrov (Expand Search), petriuov (Expand Search), petruuov (Expand Search), petrouov (Expand Search)
petruuiov » petriuuiov (Expand Search), petruuuiov (Expand Search), petrouuiov (Expand Search)
petruoiov » petriuoiov (Expand Search), petruuoiov (Expand Search), petrouoiov (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 ((petruuiov OR petruoiov) OR ((petroi OR (petriov OR petruov)) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruuiov OR petruoiov) OR ((petroi OR (petriov OR petruov)) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petruuiov OR petruoiov) OR ((petroi OR (petriov OR petruov)) OR (petr OR peter))) o.s.*.