Perhaps you should try some spelling variations:
"bioenergy tree adoption" » "bioenergy trees adoption", "bioenergy trade adoption", "bioenergy from adoption", "bioenergy time adoption", "bioenergy ieee adoption", "bioenergy pre adoption"
"bioenergy der adoption" » "bioenergy dna adoption", "bioenergy part adoption", "bioenergy _ adoption", "bioenergy user adoption"

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: "((\"bioenergy der adoption\") OR (\"bioenergy tree adoption\"))".
• Removing quotes may allow a broader search: (( bioenergy der adoption ) OR ( bioenergy tree adoption )).
• Adding a wildcard symbol may retrieve word variants: (("bioenergy der adoption") OR ("bioenergy tree adoption"))*.