Perhaps you should try some spelling variations:
"an introduction _ computer programmingrs" » "an introduction _ computer programming" (Expand search), "an introduction _ computers programming" (Expand search), "an introduction _ computer programmers" (Expand search)
"advanced python python computer programa" » "advanced python python computer program" (Expand search), "advanced python python computer programs" (Expand search), "advanced python python computer programme" (Expand search), "advanced method python computer programa" (Expand search), "advanced path python computer programa" (Expand search), "advanced symphony python computer programa" (Expand search), "advanced pythons python computer programa" (Expand search), "advanced piton python computer programa" (Expand search), "advanced pitons python computer programa" (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: "((\"an introduction _ computer programmingrs\") OR (\"advanced python python computer programa\"))~".
• Removing quotes may allow a broader search: (( an introduction _ computer programmingrs ) OR ( advanced python python computer programa ))~.
• Adding a wildcard symbol may retrieve word variants: (("an introduction _ computer programmingrs") OR ("advanced python python computer programa"))*.