Perhaps you should try some spelling variations:
peterov » petrov (Expand Search)
petroow » petrow (Expand Search), peteroow (Expand Search), petruoow (Expand Search), petrooow (Expand Search)
peterow » petrow (Expand Search)
petris » peteris (Expand Search), petruis (Expand Search), petrois (Expand Search)
petr » peter (Expand Search), petru (Expand Search), petro (Expand Search)
petri » peteri (Expand Search), petrui (Expand Search), petroi (Expand Search)
peters » peter (Expand Search), petersen (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 (((peterov OR peroov) OR petris) OR (((petroow OR peterow) OR (petr OR peters)) OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((peterov OR peroov) OR petris) OR (((petroow OR peterow) OR (petr OR peters)) OR petri)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((peterov OR peroov) OR petris) OR (((petroow OR peterow) OR (petr OR peters)) OR petri)) o.s.*.