Perhaps you should try some spelling variations:
petroov » peteroov (Expand Search), petruoov (Expand Search), petrooov (Expand Search)
petriov » peteriov (Expand Search), petruiov (Expand Search), petroiov (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
petroi » peteroi (Expand Search), petruoi (Expand Search), petrooi (Expand Search)
petrooi » peterooi (Expand Search), petruooi (Expand Search), petroooi (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 ((petroov OR (petriov OR peteruiov)) OR ((petri OR (petroi OR petrooi)) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroov OR (petriov OR peteruiov)) OR ((petri OR (petroi OR petrooi)) OR petr)) o.s.*".