Perhaps you should try some spelling variations:
petroiov » petrov (Expand Search), peteroiov (Expand Search), petrooiov (Expand Search), peroiov (Expand Search)
peru » per (Expand Search)
peterovu » petrov (Expand Search)
petriov » peteriov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petru » peteru (Expand Search), petrou (Expand Search), peru (Expand Search)
petri » peteri (Expand Search), petroi (Expand Search), peri (Expand Search)
petr » peter (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 ((petriov OR petroiov) OR (((petru OR peru) OR peterovu) OR ((pero OR petri) OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR petroiov) OR (((petru OR peru) OR peterovu) OR ((pero OR petri) OR petr))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR petroiov) OR (((petru OR peru) OR peterovu) OR ((pero OR petri) OR petr))) o.s.*.