Perhaps you should try some spelling variations:
petroov » peteroov (Expand Search), petrioov (Expand Search), petruoov (Expand Search)
petriv » peteriv (Expand Search), petriiv (Expand Search), petruiv (Expand Search)
petruiv » peteruiv (Expand Search), petriuiv (Expand Search), petruuiv (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search)
petriuo » peteriuo (Expand Search), petriiuo (Expand Search), petruiuo (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 ((petroov OR (petriv OR petruiv)) OR (((petrui OR petroi) OR petriuo) OR (pero OR petr))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petroov OR (petriv OR petruiv)) OR (((petrui OR petroi) OR petriuo) OR (pero OR petr))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petroov OR (petriv OR petruiv)) OR (((petrui OR petroi) OR petriuo) OR (pero OR petr))) o.s.*.