Perhaps you should try some spelling variations:
management schemes » management scheme, management systemen, management science
etc general » c general
sic general » music general, c general, logic general
2c general » 22c general, c general, mnc general

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: %22economics%management schemes%((((2c general) OR (etc general))) OR (sic general))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22economics%management schemes%((((2c general) OR (etc general))) or (sic general))%22".
• Adding a wildcard symbol may retrieve word variants: %22economics%management schemes%((((2c general) OR (etc general))) or (sic general))%22*.