Perhaps you should try some spelling variations:
irrigation requirements » irrigation equipment, nutrition requirements
requirements primer » requirements prior, requirements power, requirements pre
primer dimensional » higher dimensional, five dimensional, lower dimensional
array imaging » arrays imaging, airway imaging, ray imaging
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: irrigation requirements primer dimensional ((array string) or (array imaging))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: irrigation requirements primer dimensional ((array string) OR (array imaging)).
• Adding a wildcard symbol may retrieve word variants: irrigation requirements primer dimensional ((array string) or (array imaging))*.