Perhaps you should try some spelling variations:
"coder coder cognitive radio problems" » "coder codex cognitive radio problems" (Expand search), "coder lower cognitive radio problems" (Expand search), "coder modes cognitive radio problems" (Expand search), "coder coder cognitive reading problems" (Expand search), "coder coder cognitive medio problemas" (Expand search), "coder coder cognitive radial problema" (Expand search), "coder decoder cognitive radio problems" (Expand search), "code code cognitive radio problems" (Expand search), "decoder codec cognitive radio problems" (Expand search)
"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)

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 cognitive radio problems") OR ("and python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder cognitive radio problems\") OR (\"and python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder cognitive radio problems ) OR ( and python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder cognitive radio problems") OR ("and python python python programming"))*.