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

• Performing a fuzzy search may retrieve terms with similar spellings: propagation models (rain OR main) and weather effects on ratio communication~.
• If you are trying to use Boolean operators, they must be ALL CAPS: propagation models (rain OR main) AND weather effects on ratio communication.
• The words AND, OR and NOT may confuse the search; try adding quotes: "propagation models (rain OR main) and weather effects on ratio communication".
• Adding a wildcard symbol may retrieve word variants: propagation models (rain OR main) and weather effects on ratio communication*.