Perhaps you should try some spelling variations:
peteriov » petrov (Expand Search)
periov » petriov (Expand Search), perov (Expand Search)
peri » petri (Expand Search), per (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petriu » peteriu (Expand Search), petriiu (Expand Search), petruiu (Expand Search)
petriou » peteriou (Expand Search), petriiou (Expand Search), petruiou (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 (peteriov OR periov)) OR (((peri OR petriu) OR petriou) OR (pero OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR (peteriov OR periov)) OR (((peri OR petriu) OR petriou) OR (pero OR petr))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR (peteriov OR periov)) OR (((peri OR petriu) OR petriou) OR (pero OR petr))) o.s.*.