Perhaps you should try some spelling variations:
invasive studies » noninvasive studies, invasive species, invasive study
algae studies » algal studies, aquae studies, algae strains
algae species » algal species, larvae species, novae species

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: ((((algae studies) OR (algae species))) OR (invasive studies)) in adult education AND lifelong learning.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((algae studies) OR (algae species))) or (invasive studies)) in adult education and lifelong learning".
• Adding a wildcard symbol may retrieve word variants: ((((algae studies) OR (algae species))) or (invasive studies)) in adult education and lifelong learning*.