Perhaps you should try some spelling variations:
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petruiiv (Expand Search)
petriiuv » peteriiuv (Expand Search), petriiiuv (Expand Search), petruiiuv (Expand Search)
petruiiuv » peteruiiuv (Expand Search), petriuiiuv (Expand Search), petruuiiuv (Expand Search)
petrio » peterio (Expand Search), petriio (Expand Search), petruio (Expand Search)
petruiio » peteruiio (Expand Search), petriuiio (Expand Search), petruuiio (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 ((petriiv OR (petriiuv OR petruiiuv)) OR (((petrio OR petruiio) OR petero) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriiv OR (petriiuv OR petruiiuv)) OR (((petrio OR petruiio) OR petero) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriiv OR (petriiuv OR petruiiuv)) OR (((petrio OR petruiio) OR petero) OR petr)) o.s.*.