Perhaps you should try some spelling variations:
irrigation requirements » irrigation equipment, nutrition requirements
space dimension » space dimensions, space division
based extension » based extraction
array string » arrays strings, array sharing, array forming
array strong » array sharing, norway strong, stay strong

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

• Performing a fuzzy search may retrieve terms with similar spellings: irrigation requirements ((space dimension) or (based extension)) ((array string) or (array strong))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: irrigation requirements ((space dimension) OR (based extension)) ((array string) OR (array strong)).
• Adding a wildcard symbol may retrieve word variants: irrigation requirements ((space dimension) or (based extension)) ((array string) or (array strong))*.