Perhaps you should try some spelling variations:
surface extension » surfaces extension, surface tension, surface expression
variation image » variational image, radiation image, navigation image
image surface » images surface, imaging surface, simple surface
array imaging » arrays imaging, airway imaging, ray imaging
array string » array strong, arrays strings, array sharing
array arcing » array forming, array probing, array sharing

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

• Performing a fuzzy search may retrieve terms with similar spellings: variation image surface extension ((((array imaging) or (array string))) or (array arcing))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: variation image surface extension ((((array imaging) OR (array string))) OR (array arcing)).
• Adding a wildcard symbol may retrieve word variants: variation image surface extension ((((array imaging) or (array string))) or (array arcing))*.