Perhaps you should try some spelling variations:
petriv » petris (Expand Search), petrov (Expand Search), peteriv (Expand Search), petruiv (Expand Search), petroiv (Expand Search)
peters » peter (Expand Search), petersen (Expand Search)
petrio » petris (Expand Search), petro (Expand Search), peterio (Expand Search), petruio (Expand Search), petroio (Expand Search)
petruuuiv » peteruuuiv (Expand Search), petruuuuiv (Expand Search), petrouuuiv (Expand Search)
petroui » peteroui (Expand Search), petruoui (Expand Search), petrooui (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (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 ((petriv OR petruuuiv) OR (((peters OR petroui) OR petrio) OR (petr OR petri))) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petriv OR petruuuiv) OR (((peters OR petroui) OR petrio) OR (petr OR petri))) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((petriv OR petruuuiv) OR (((peters OR petroui) OR petrio) OR (petr OR petri))) o.s.*.