Perhaps you should try some spelling variations:
communication conversion » communication conversation, communications convention, communication cohesion
conversion based » conversion del, conversion a, converter based
based discussion » brief discussion
food wastes » food waste, wood waste, solid wastes
from water » from waste
from wave » from waves, from cave, from wage

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

• Performing a fuzzy search may retrieve terms with similar spellings: communication conversion based discussion ((from wave) or (((from water) or (food wastes))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communication conversion based discussion ((from wave) OR (((from water) OR (food wastes)))).
• Adding a wildcard symbol may retrieve word variants: communication conversion based discussion ((from wave) or (((from water) or (food wastes))))*.