Perhaps you should try some spelling variations:
"waste heavy recovery" » "waste heat recovery", "waste easy recovery", "waste heart recovery", "fast heavy recovery", "late heavy recovery"
"waste head recovery" » "waste heat recovery", "waste lead recovery", "waste dead recovery", "waste heap recovery", "waste cheap recovery"

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: "((\"waste head recovery\") OR (\"waste heavy recovery\"))".
• Removing quotes may allow a broader search: (( waste head recovery ) OR ( waste heavy recovery )).
• Adding a wildcard symbol may retrieve word variants: (("waste head recovery") OR ("waste heavy recovery"))*.