Perhaps you should try some spelling variations:
"acta slavica estonie" » "anna slavina estonie", "art slavic estonie"
"acta slavica festgabe" » "anna slavina festgabe", "art slavic festgabe"
"et slavica estonie" » "res slavica estonie", "_ slavica estonie"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("acta slavica estonie") OR ("et slavica estonie"))) OR ("acta slavica festgabe")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"acta slavica estonie\") OR (\"et slavica estonie\"))) or (\"acta slavica festgabe\"))".
• Removing quotes may allow a broader search: (((( acta slavica estonie ) OR ( et slavica estonie ))) or ( acta slavica festgabe )).
• Adding a wildcard symbol may retrieve word variants: (((("acta slavica estonie") OR ("et slavica estonie"))) or ("acta slavica festgabe"))*.