Perhaps you should try some spelling variations:
"and introduction _ computer programmingrs" » "and introduction _ computer programming" (Expand search), "and introduction _ computers programming" (Expand search), "and introduction _ computer programing" (Expand search), "an introduction _ computer programmingrs" (Expand search)
"advanced python python computer programmers" » "advanced python python computer programs" (Expand search), "advanced python python computer programming" (Expand search), "advanced python python computers programming" (Expand search), "advanced method python computer programmers" (Expand search), "advanced path python computer programmers" (Expand search), "advanced symphony python computer programmers" (Expand search), "advanced pythons python computer programmers" (Expand search), "advanced piton python computer programmers" (Expand search), "advanced pitons python computer programmers" (Expand search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"and introduction _ computer programmingrs\") OR (\"advanced python python computer programmers\"))~".
• Removing quotes may allow a broader search: (( and introduction _ computer programmingrs ) OR ( advanced python python computer programmers ))~.
• Adding a wildcard symbol may retrieve word variants: (("and introduction _ computer programmingrs") OR ("advanced python python computer programmers"))*.