Perhaps you should try some spelling variations:
irrigation requirements » irrigation equipment, nutrition requirements
requirements data » requirements a, requirements case, requirements based
data imprecision » based imprecision, table imprecision, data compression
imprecision a » imprecision _, precision a, precision _
a pectin » _ pectin, a pecan

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 data imprecision a pectin~.
• Adding a wildcard symbol may retrieve word variants: irrigation requirements data imprecision a pectin*.