Perhaps you should try some spelling variations:
information documents » information documentation, information requirements
information agents » information age, information access, information about
extension model » extension modes, extensional model, extension modeling
fair extension » farm extension, major extension, base extension
model like » model life, model lake, model lie

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((information documents) or (information agents)) fair extension model like~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((information documents) OR (information agents)) fair extension model like.
• Adding a wildcard symbol may retrieve word variants: ((information documents) or (information agents)) fair extension model like*.