Perhaps you should try some spelling variations:
surface diffusion » state diffusion
information gain » information gap, information guide, information gathering
array planning » library planning, therapy planning
gain surface » grain surface, rain surface, brain surface
array string » array strong, arrays strings, array sharing
array using » arrays using

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

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