Perhaps you should try some spelling variations:
information estimation » deformation estimation, information motivation, information extraction
estimation system » automation system, animation system
array formulas » area formulas, harrop formulas, array formats
system recent » systems recent, system revenue, system report
array using » arrays using

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

• Performing a fuzzy search may retrieve terms with similar spellings: information estimation system recent ((((array formulas) or (array format))) or (array using))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: information estimation system recent ((((array formulas) OR (array format))) OR (array using)).
• Adding a wildcard symbol may retrieve word variants: information estimation system recent ((((array formulas) or (array format))) or (array using))*.