Perhaps you should try some spelling variations:
naturalistic approach » pluralistic approach, heuristic approach, realistic approach
futuristic approach » heuristic approach, metaheuristic approach, heuristic approaches
humanistic approach » mechanistic approach, holistic approach, heuristic approach

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: ((naturalistic approach) OR (((futuristic approach) OR (humanistic approach)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((naturalistic approach) or (((futuristic approach) OR (humanistic approach))))".
• Adding a wildcard symbol may retrieve word variants: ((naturalistic approach) or (((futuristic approach) OR (humanistic approach))))*.