Perhaps you should try some spelling variations:
significant variation » significant variations (Expand Search), significant association (Expand Search), significant correlation (Expand Search)
variation paths » variation graphs (Expand Search), variation patterns (Expand Search), variation within (Expand Search)
step decrease » sizes decrease (Expand Search), teer decrease (Expand Search), we decrease (Expand Search)
mean decrease » a decrease (Expand Search)

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: "(( significant ((step decrease) OR (mean decrease)) ) OR ( significant variation paths ))~".
• Adding a wildcard symbol may retrieve word variants: (( significant ((step decrease) OR (mean decrease)) ) OR ( significant variation paths ))*.