Perhaps you should try some spelling variations:
"mail business books" » "mail business book", "mail business handbooks", "mail business yearbooks", "small business books", "retail business books", "small businesses books"
"mail business costs" » "mail business cases", "mail business customs", "mail business centers", "small business costs", "retail business costs", "small businesses costs"
"bass business case" » "sas business case", "bass business cycle", "bass business climate"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("mail business books") OR ("mail business costs"))) OR ("bass business case"))~.
• Removing quotes may allow a broader search: (((( mail business books ) or ( mail business costs ))) or ( bass business case ))~.
• Adding a wildcard symbol may retrieve word variants: (((("mail business books") or ("mail business costs"))) or ("bass business case"))*.