Perhaps you should try some spelling variations:
functions functional » equations functional
functional spatial » functional status, functional spaces, functional state
spatial dimensions » social dimensions, social dimension, political dimensions
array devicen » array devices, airway devices, array design
array device » airway devices, array design, array drive
array pixel » array pixels

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

• If you are trying to use Boolean operators, they must be ALL CAPS: functions functional spatial dimensions ((((array devicen) OR (array device))) OR (array pixel))~.
• Adding a wildcard symbol may retrieve word variants: functions functional spatial dimensions ((((array devicen) or (array device))) or (array pixel))*.