Perhaps you should try some spelling variations:
source diffusion » resource diffusion, surface diffusion, double diffusion
array formulas » area formulas, harrop formulas, array format
guide source » guides resource, oxide sources, guide your
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: information guide source diffusion ((array string) or (((array formulas) or (array arcing))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: information guide source diffusion ((array string) OR (((array formulas) OR (array arcing)))).
• Adding a wildcard symbol may retrieve word variants: information guide source diffusion ((array string) or (((array formulas) or (array arcing))))*.