Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
bans irrigation » canal irrigation, basin irrigation, farm irrigation
banking series » banking services, banking service, banking crises
export bans » export base, export bias, import bans
import duty » import duties

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( export bans irrigation schemes. ) or ( ((import data) OR (import duty)) banking series. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( export bans irrigation schemes. ) OR ( ((import data) OR (import duty)) banking series. )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( export bans irrigation schemes. ) or ( ((import data) OR (import duty)) banking series. ))".
• Adding a wildcard symbol may retrieve word variants: (( export bans irrigation schemes. ) or ( ((import data) OR (import duty)) banking series. ))*.