Perhaps you should try some spelling variations:
"flood management activity." » "flood management activities.", "flood management facility.", "flood management authority.", "fund management activity."
"land management activity." » "land management activities.", "land management facility.", "land management authority."
"reform management tools." » "farm management tools."
"chain management contracts." » "cash management contracts."
"firm management case." » "farm management case.", "fire management case.", "city management case.", "firm management a."
"firm management how." » "farm management how.", "fire management how.", "city management how.", "firm management from.", "firm management a."
"side management _." » "case management _.", "zone management _.", "service management _."

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: (((((((("risk management control.") OR ("chain management contracts."))) OR ((("flood management activity.") OR ("land management activity."))))) OR ((("firm management case.") OR ((("side management _.") OR ("firm management how."))))))) OR ("reform management tools."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((((\"risk management control.\") or (\"chain management contracts.\"))) or (((\"flood management activity.\") OR (\"land management activity.\"))))) or (((\"firm management case.\") or (((\"side management _.\") or (\"firm management how.\"))))))) or (\"reform management tools.\"))~".
• Removing quotes may allow a broader search: (((((((( risk management control. ) or ( chain management contracts. ))) or ((( flood management activity. ) OR ( land management activity. ))))) or ((( firm management case. ) or ((( side management _. ) or ( firm management how. ))))))) or ( reform management tools. ))~.
• Adding a wildcard symbol may retrieve word variants: (((((((("risk management control.") or ("chain management contracts."))) or ((("flood management activity.") OR ("land management activity."))))) or ((("firm management case.") or ((("side management _.") or ("firm management how."))))))) or ("reform management tools."))*.