Perhaps you should try some spelling variations:
petruiov » petrov (Expand Search), peteruiov (Expand Search), petruuiov (Expand Search), petrouiov (Expand Search)
petriiov » petrov (Expand Search), peteriiov (Expand Search), petruiiov (Expand Search), petroiiov (Expand Search)
peri » per (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petruiuui » peteruiuui (Expand Search), petruuiuui (Expand Search), petrouiuui (Expand Search)
petr » peter (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 (petruiov OR petriiov)) OR ((petri OR (peri OR petruiuui)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriov OR (petruiov OR petriiov)) OR ((petri OR (peri OR petruiuui)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriov OR (petruiov OR petriiov)) OR ((petri OR (peri OR petruiuui)) OR petr)) o.s.*.