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