Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
bans irrigation » tank irrigation, canal irrigation, basin irrigation
state banking » state banks, state bank
data banking » data taking, data linking, data asking
export bans » export base, export bias, import bans

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: (( export bans irrigation schemes. ) OR ( import ((data banking) OR (state banking)) series. ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( export bans irrigation schemes. ) or ( import ((data banking) OR (state banking)) series. ))~".
• Adding a wildcard symbol may retrieve word variants: (( export bans irrigation schemes. ) or ( import ((data banking) OR (state banking)) series. ))*.