Perhaps you should try some spelling variations:
petroiov » petrov (Expand Search), peteroiov (Expand Search), petrioiov (Expand Search), petruoiov (Expand Search)
petriiov » petrov (Expand Search), peteriiov (Expand Search), petriiiov (Expand Search), petruiiov (Expand Search)
peterui » peterdi (Expand Search)
petriov » peteriov (Expand Search), petriiov (Expand Search), petruiov (Expand Search)
petroiv » peteroiv (Expand Search), petrioiv (Expand Search), petruoiv (Expand Search)
petriuoi » peteriuoi (Expand Search), petriiuoi (Expand Search), petruiuoi (Expand Search)
petr » peter (Expand Search), petri (Expand Search), petru (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 ((((petriov OR petroiov) OR petriiov) OR petroiv) OR ((peterui OR petriuoi) OR petr)) o.s.~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "fop ((((petriov OR petroiov) OR petriiov) OR petroiv) OR ((peterui OR petriuoi) OR petr)) o.s.".
• Adding a wildcard symbol may retrieve word variants: fop ((((petriov OR petroiov) OR petriiov) OR petroiv) OR ((peterui OR petriuoi) OR petr)) o.s.*.