Perhaps you should try some spelling variations:
peterov » petrov (Expand Search)
petruv » petru (Expand Search), petrov (Expand Search), petruuv (Expand Search), petrouv (Expand Search), peruv (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)
petroiio » petruoiio (Expand Search), petrooiio (Expand Search), peroiio (Expand Search)
petruio » petruuio (Expand Search), petrouio (Expand Search), peruio (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (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 (((petri OR peterov) OR petruv) OR ((petroiio OR petruio) OR (petr OR peter))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((petri OR peterov) OR petruv) OR ((petroiio OR petruio) OR (petr OR peter))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((petri OR peterov) OR petruv) OR ((petroiio OR petruio) OR (petr OR peter))) o.s.*.