Perhaps you should try some spelling variations:
"varying environments and operational considerations" » "varying environments and computational considerations", "varying environments and additional considerations", "varying environment and operational considerations", "learning environments and operational considerations", "working environments and operational considerations"
"varying environments and operational conditions" » "varying environments and operating conditions", "varying environments and operational definitions", "varying environments and operational control", "varying environment and operational conditions", "learning environments and operational conditions", "working environments and operational conditions"

Try widening your search to All Fields.

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: "((\"varying environments and operational conditions\") OR (\"varying environments and operational considerations\"))".
• Removing quotes may allow a broader search: (( varying environments and operational conditions ) OR ( varying environments and operational considerations )).
• Adding a wildcard symbol may retrieve word variants: (("varying environments and operational conditions") OR ("varying environments and operational considerations"))*.