Perhaps you should try some spelling variations:
studying expression » studying depression, student expression, studies expression
array forming » array format, array arcing, array fermi
array imaging » arrays imaging, airway imaging, ray imaging
its studying » iltis studying, vos studying, grids studying
array string » array strong, arrays strings, 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 its studying expression ((array string) or (((array forming) or (array imaging))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: information its studying expression ((array string) OR (((array forming) OR (array imaging)))).
• Adding a wildcard symbol may retrieve word variants: information its studying expression ((array string) or (((array forming) or (array imaging))))*.