Perhaps you should try some spelling variations:
significantly observed » significantly altered (Expand Search), significantly clustered (Expand Search), significantly preferred (Expand Search)
significantly smaller » significantly larger (Expand Search), significantly shorter (Expand Search), significantly higher (Expand Search)
observed decrease » observed decreased (Expand Search)
smaller decrease » small decrease (Expand Search), marked decrease (Expand Search), smaller areas (Expand Search)

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

• Removing quotes may allow a broader search: (( significantly smaller decrease ) OR ( significantly observed decrease )).