Perhaps you should try some spelling variations:
"testhefte e poetica" » "testheften i poetica", "testheft i poetica", "testheft der poetica", "testhefte de poetica", "testhefte et poeticae", "testhefte _ poetical"
"leithefte zu poetica" » "leithefte la poetica", "leithefte de poetica", "leithefte et poetica"
"leithefte da poetica" » "leithefte la poetica", "leithefte de poetica", "leithefte una poetica", "leithefte da poetical", "leithefte dla poetica", "leithefte da poetic"
"lesehefte a poetica" » "lesehefte a poetical", "lesehefte la poetica", "lesehefte a poetic", "leseheft a poetica"
"lesehefte e poetica" » "lesehefte de poetica", "lesehefte et poeticae", "lesehefte _ poetical", "leseheft e poetica"

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: (((("leithefte zu poetica") OR ("leithefte da poetica"))) OR ((("lesehefte a poetica") OR ((("lesehefte e poetica") OR ("testhefte e poetica")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"leithefte zu poetica\") OR (\"leithefte da poetica\"))) or (((\"lesehefte a poetica\") or (((\"lesehefte e poetica\") or (\"testhefte e poetica\"))))))".
• Removing quotes may allow a broader search: (((( leithefte zu poetica ) OR ( leithefte da poetica ))) or ((( lesehefte a poetica ) or ((( lesehefte e poetica ) or ( testhefte e poetica )))))).
• Adding a wildcard symbol may retrieve word variants: (((("leithefte zu poetica") OR ("leithefte da poetica"))) or ((("lesehefte a poetica") or ((("lesehefte e poetica") or ("testhefte e poetica"))))))*.