Perhaps you should try some spelling variations:
significant calibration » significant variation (Expand Search), significant alterations (Expand Search), significant migration (Expand Search)
calibration methods » calibration method (Expand Search), validation methods (Expand Search), calculation method (Expand Search)
step decrease » sizes decrease (Expand Search), teer decrease (Expand Search), we decrease (Expand Search)
a decrease » _ decrease (Expand Search), _ decreased (Expand Search), _ decreases (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 (a decrease)) ) OR ( significant calibration methods ))~".
• Adding a wildcard symbol may retrieve word variants: (( significant ((step decrease) OR (a decrease)) ) OR ( significant calibration methods ))*.