Perhaps you should try some spelling variations:
petr » peter (Expand Search), petri (Expand Search), petru (Expand Search)
petroi » peteroi (Expand Search), petrioi (Expand Search), petruoi (Expand Search), petri (Expand Search), petro (Expand Search), petrov (Expand Search)
petrioi » peterioi (Expand Search), petriioi (Expand Search), petruioi (Expand Search)
petrui » peterui (Expand Search), petriui (Expand Search), petruui (Expand Search), petri (Expand Search), petru (Expand Search)
petrooi » peterooi (Expand Search), petriooi (Expand Search), petruooi (Expand Search)
peters » peter (Expand Search), petersen (Expand Search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((petr OR peters) OR (((petroi OR petrioi) OR petrui) OR petrooi)) _. s.~".
• Adding a wildcard symbol may retrieve word variants: fop ((petr OR peters) OR (((petroi OR petrioi) OR petrui) OR petrooi)) _. s.*.