Perhaps you should try some spelling variations:
peters » petersen (Expand Search)
petrou » petru (Expand Search), petro (Expand Search), petrow (Expand Search), petruou (Expand Search), petroou (Expand Search), perou (Expand Search)
petr » petru (Expand Search), petro (Expand Search), per (Expand Search)
petrov » petruov (Expand Search), petroov (Expand Search), perov (Expand Search), petro (Expand Search)
petruov » petruuov (Expand Search), petrouov (Expand Search), peruov (Expand Search)
petri » petrui (Expand Search), petroi (Expand Search), peri (Expand Search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: fop ((peters OR (petrou OR (petr OR (petrov OR petruov)))) OR (peter OR petri)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((peters OR (petrou OR (petr OR (petrov OR petruov)))) OR (peter OR petri)) o.s.*".