Perhaps you should try some spelling variations:
"coder arc routing algorithm validation" » "coder arc routing algorithm evaluation" (Expand search), "coder arc routing algorithm application" (Expand search), "coder arc routing algorithms evaluation" (Expand search), "coder arc clustering algorithm validation" (Expand search), "codes marc routing algorithm validation" (Expand search), "code art routing algorithm validation" (Expand search), "code are routing algorithm validation" (Expand search)
"api pitons python python programming" » "api pitons pythons python programming" (Expand search), "api pitons piton python programming" (Expand search), "api pitons pytm python programming" (Expand search), "api citons python python programming" (Expand search), "api pitoni python python programming" (Expand search), "api pitoes python python programming" (Expand search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("coder arc routing algorithm validation") OR ("api pitons python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder arc routing algorithm validation\") OR (\"api pitons python python programming\"))".
• Removing quotes may allow a broader search: (( coder arc routing algorithm validation ) OR ( api pitons python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder arc routing algorithm validation") OR ("api pitons python python programming"))*.