Perhaps you should try some spelling variations:
petra » petro (Expand Search), petre (Expand Search), petroa (Expand Search), pera (Expand Search)
petru » pentru (Expand Search), petrou (Expand Search), peru (Expand Search)
petrou » petro (Expand Search), petrov (Expand Search), petrow (Expand Search), petroou (Expand Search), perou (Expand Search)
petriov » petrov (Expand Search), petroiov (Expand Search), periov (Expand Search)
petroov » petrov (Expand Search), petrooov (Expand Search), peroov (Expand Search)
petri » petroi (Expand Search), peri (Expand Search)
petr » petro (Expand Search), per (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 (((((petra OR petri) OR (petru OR petrou)) OR (petriov OR petroov)) OR petr) OR peter) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop (((((petra OR petri) OR (petru OR petrou)) OR (petriov OR petroov)) OR petr) OR peter) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop (((((petra OR petri) OR (petru OR petrou)) OR (petriov OR petroov)) OR petr) OR peter) o.s.*.