Perhaps you should try some spelling variations:
educational disparities » educational authorities, educational distribution
national authorities » local authorities
output data » output ratio
data ape » data age, data paper, data a
agricultural » agriculture

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

• Performing a fuzzy search may retrieve terms with similar spellings: agricultural output data ape ((educational disparities) or (national authorities)).~.
• If you are trying to use Boolean operators, they must be ALL CAPS: agricultural output data ape ((educational disparities) OR (national authorities))..
• Adding a wildcard symbol may retrieve word variants: agricultural output data ape ((educational disparities) or (national authorities)).*.