Perhaps you should try some spelling variations:
irrigation systemss » irrigation system, irrigation schemes, navigation systems
urban irrigation » murray irrigation, grain irrigation, gray irrigation
basin irrigation » drip irrigation, canal irrigation, farm irrigation
supply basin » supply asia, supply based, supply design
systems. » system.
systemss. » systems.

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: (( supply basin irrigation systems. ) OR ( supply urban irrigation systemss. ))~.
• Adding a wildcard symbol may retrieve word variants: (( supply basin irrigation systems. ) or ( supply urban irrigation systemss. ))*.