Perhaps you should try some spelling variations:
introduction conceptual » introduction concepts
programming recursion » programming decision, programming session, programming decisions
programming defining » programming designing, programming learning, programming reasoning
basic truss » basics truss, basic struts, basic truth

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: introduction conceptual ((programming defining) OR (programming recursion)) basic truss~.
• Adding a wildcard symbol may retrieve word variants: introduction conceptual ((programming defining) or (programming recursion)) basic truss*.