Perhaps you should try some spelling variations:
observational context » observational concepts, observational contacts, observationsin contexts
observational clues » observational aspects, observational results, observational techniques
observation content » observation concept, observation consistent, observation concepts

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: ((observational clues) OR (((observation content) OR (observational context)))).
• Adding a wildcard symbol may retrieve word variants: ((observational clues) or (((observation content) or (observational context))))*.