Perhaps you should try some spelling variations:
"retail business books" » "retail businesses books", "rural business books", "central business books", "retail business book", "retail business handbooks", "retail business yearbooks"
"basic business costs" » "bass business costs", "asia business costs", "based business costs", "basic business cases", "basic business customs", "basic business case"
"mail business hours" » "small business hours", "small businesses hours"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"retail business books\") OR (((\"basic business costs\") OR (\"mail business hours\"))))~".
• Removing quotes may allow a broader search: (( retail business books ) OR ((( basic business costs ) OR ( mail business hours ))))~.
• Adding a wildcard symbol may retrieve word variants: (("retail business books") OR ((("basic business costs") OR ("mail business hours"))))*.