Perhaps you should try some spelling variations:
growth interactions » group interactions, growth international, through interactions
interactions series » interactions between
irrigation schemes » irrigation scheme, irrigation systems
gray irrigation » grain irrigation, gravity irrigation, murray irrigation
supply gray » supply great, supply gap, supply gas

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 growth interactions series. ) OR ( supply gray irrigation schemes. ))~.
• Adding a wildcard symbol may retrieve word variants: (( supply growth interactions series. ) or ( supply gray irrigation schemes. ))*.