Perhaps you should try some spelling variations:
"acta slavica estonia" » "acta latvia estonia", "anna slavina estonia", "art slavic estonia", "et slavica estonia"
"castle slovenia estonia" » "castle slowakia estonia", "chile slovenia estonia", "eastern slovenia estonia"
"east slovenia estonia" » "art slovenia estonia", "eastern slovenia estonia", "egypt slovenia estonia"

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 estonia") OR ((("east slovenia estonia") OR ("castle slovenia estonia")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"acta slavica estonia\") or (((\"east slovenia estonia\") OR (\"castle slovenia estonia\"))))".
• Removing quotes may allow a broader search: (( acta slavica estonia ) or ((( east slovenia estonia ) OR ( castle slovenia estonia )))).
• Adding a wildcard symbol may retrieve word variants: (("acta slavica estonia") or ((("east slovenia estonia") OR ("castle slovenia estonia"))))*.