Perhaps you should try some spelling variations:
"pollutants dispersion reduction" » "pollutant dispersion reduction", "pollution dispersion reduction", "pollutants detection reduction", "pollutants dispersion prediction", "pollutants dispersion predictions", "pollutants dispersion relation"
"pollutant dimension reduction" » "pollutant dispersion reduction", "pollutant diffusion reduction", "pollution dimensions reduction", "pollutant dimensionality reduction"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"pollutant dimension reduction\") OR (\"pollutants dispersion reduction\"))".
• Removing quotes may allow a broader search: (( pollutant dimension reduction ) OR ( pollutants dispersion reduction )).
• Adding a wildcard symbol may retrieve word variants: (("pollutant dimension reduction") OR ("pollutants dispersion reduction"))*.