Perhaps you should try some spelling variations:
"coder coder channel allocation problem" » "coder coder channel location problem" (Expand search), "coder codes channel allocation problem" (Expand search), "coder adder channel allocation problem" (Expand search), "coder color channel allocation problem" (Expand search), "coder decoder channel allocation problem" (Expand search), "code code channel allocation problem" (Expand search), "decoder codec channel allocation problem" (Expand search)
"on python python python programming" » "on pythons python python programming" (Expand search), "on piton python python programming" (Expand search), "on pitons python python programming" (Expand search), "in python pythin python programming" (Expand search), "of python pythof python programming" (Expand search), "_ python pyth_ 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 channel allocation problem") OR ("on python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder channel allocation problem\") OR (\"on python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder channel allocation problem ) OR ( on python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder channel allocation problem") OR ("on python python python programming"))*.