Perhaps you should try some spelling variations:
"an introduction to computer programss" » "an introduction to computer programs" (Expand search), "an introduction to computer programmes" (Expand search), "an introduction to computer programme" (Expand search), "an introduction to compute programss" (Expand search), "an introduction _ computer programss" (Expand search), "an introduction by computer programss" (Expand search), "an introduction to computer programass" (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 to computer programss\") OR (\"advanced python python computer program\"))~".
• Removing quotes may allow a broader search: (( an introduction to computer programss ) OR ( advanced python python computer program ))~.
• Adding a wildcard symbol may retrieve word variants: (("an introduction to computer programss") OR ("advanced python python computer program"))*.