Perhaps you should try some spelling variations:
"and python python python programming" » "and pythons python python programming" (Expand search), "and piton python python programming" (Expand search), "and pitons python python programming" (Expand search), "in python python python programming" (Expand search), "on python python python programming" (Expand search), "api python python python programming" (Expand search)
"coder coder and routing problem" » "coder decoder and routing problem" (Expand search), "code code and routing problem" (Expand search), "decoder codec and routing problem" (Expand search), "coder coder arc routing problem" (Expand search), "coder code and routing problem" (Expand search), "coder codes and routing problem" (Expand search), "coder poder and routing problem" (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 coder and routing problem") OR ("and python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder and routing problem\") OR (\"and python python python programming\"))*".
• Removing quotes may allow a broader search: (( coder coder and routing problem ) OR ( and python python python programming ))*.