Perhaps you should try some spelling variations:
sectional studies » functional studies, regional studies, sectional study
doctoral studies » doctoral students, doctoral student, cultural studies
lake regional » lakes regional, like regional, place regional
bank regional » lanka regional, mask regional, urbano regional
park regional » parks regional, part regional, park region
world lake » world make, world take, world taken

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: (( world lake regional AND sectional studies ) OR ( world ((bank regional) OR (park regional)) AND doctoral studies )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( world lake regional and sectional studies ) or ( world ((bank regional) OR (park regional)) and doctoral studies ))".
• Adding a wildcard symbol may retrieve word variants: (( world lake regional and sectional studies ) or ( world ((bank regional) OR (park regional)) and doctoral studies ))*.