Perhaps you should try some spelling variations:
"waste management activity." » "waste management activities.", "waste management facility.", "waste management authority.", "debt management activity."
"cash management centers." » "cash management controls.", "cash management energy.", "cash management entity."
"asset management centers." » "asset management controls.", "asset management energy.", "asset management entity.", "debt management centers."
"demand management control." » "debt management control."
"land management water." » "land management data.", "land management based.", "land management a."
"flood management case." » "fund management case.", "flood management a."

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 contracts.") OR ((("land management water.") OR ("flood management case."))))) OR ((((((("cash management centers.") OR ("asset management centers."))) OR ("waste management activity."))) OR ("service management concepts."))))) OR ("demand management control."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"risk management contracts.\") or (((\"land management water.\") or (\"flood management case.\"))))) or (((((((\"cash management centers.\") OR (\"asset management centers.\"))) or (\"waste management activity.\"))) or (\"service management concepts.\"))))) or (\"demand management control.\"))~".
• Removing quotes may allow a broader search: (((((( risk management contracts. ) or ((( land management water. ) or ( flood management case. ))))) or ((((((( cash management centers. ) OR ( asset management centers. ))) or ( waste management activity. ))) or ( service management concepts. ))))) or ( demand management control. ))~.
• Adding a wildcard symbol may retrieve word variants: (((((("risk management contracts.") or ((("land management water.") or ("flood management case."))))) or ((((((("cash management centers.") OR ("asset management centers."))) or ("waste management activity."))) or ("service management concepts."))))) or ("demand management control."))*.