Perhaps you should try some spelling variations:
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petruoi » peteruoi (Expand Search), petriuoi (Expand Search), petruuoi (Expand Search)
petruui » peteruui (Expand Search), petriuui (Expand Search), petruuui (Expand Search)
petrooio » peterooio (Expand Search), petriooio (Expand Search), petruooio (Expand Search)
petrouio » peterouio (Expand Search), petriouio (Expand Search), petruouio (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 ((((petroi OR petruoi) OR petruui) OR (petrooio OR petrouio)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (petriov OR ((((petroi OR petruoi) OR petruui) OR (petrooio OR petrouio)) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (petriov OR ((((petroi OR petruoi) OR petruui) OR (petrooio OR petrouio)) OR petr)) o.s.*.