Perhaps you should try some spelling variations:
"coder coder signal processing problem" » "coder coder signal pressing problem" (Expand search), "coder coder signal process problem" (Expand search), "coder coder signal processing program" (Expand search), "coder mode signal processing problem" (Expand search), "coder power signal processing problem" (Expand search), "coder power signals processing problem" (Expand search), "coder decoder signal processing problem" (Expand search), "code code signal processing problem" (Expand search), "decoder codec signal processing problem" (Expand search)
"_ python python python programming" » "_ pythons python python programming" (Expand search), "_ piton python python programming" (Expand search), "_ pitons 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 signal processing problem") OR ("_ python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder signal processing problem\") OR (\"_ python python python programming\"))*".
• Removing quotes may allow a broader search: (( coder coder signal processing problem ) OR ( _ python python python programming ))*.