Perhaps you should try some spelling variations:
petruv » peteruv (Expand Search), petruuv (Expand Search), petrouv (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petruui » peteruui (Expand Search), petruuui (Expand Search), petrouui (Expand Search)
petroui » peteroui (Expand Search), petruoui (Expand Search), petrooui (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((petruv OR (petriov OR peteroiiov)) OR (((petri OR petruui) OR petroui) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petruv OR (petriov OR peteroiiov)) OR (((petri OR petruui) OR petroui) OR petr)) o.s.*".