Perhaps you should try some spelling variations:
petriiv » peteriiv (Expand Search), petriiiv (Expand Search), petroiiv (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petroiov (Expand Search)
petriuuov » peteriuuov (Expand Search), petriiuuov (Expand Search), petroiuuov (Expand Search)
petriiuv » peteriiuv (Expand Search), petriiiuv (Expand Search), petroiiuv (Expand Search)
petru » peteru (Expand Search), petriu (Expand Search), petrou (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petro (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 petriov) OR petriuuov) OR petriiuv) OR ((petriov OR petru) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriiv OR petriov) OR petriuuov) OR petriiuv) OR ((petriov OR petru) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriiv OR petriov) OR petriuuov) OR petriiuv) OR ((petriov OR petru) OR petr)) o.s.*.