Perhaps you should try some spelling variations:
"coder coder sampling open problems" » "coder under sampling open problems" (Expand search), "coder over sampling open problems" (Expand search), "coder core sampling open problems" (Expand search), "coder coder sampling on problems" (Expand search), "coder coder sampling event problems" (Expand search), "coder coder sampling of problems" (Expand search), "coder decoder sampling open problems" (Expand search), "code code sampling open problems" (Expand search), "decoder codec sampling open problems" (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 sampling open problems") OR ("on python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder sampling open problems\") OR (\"on python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder sampling open problems ) OR ( on python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder sampling open problems") OR ("on python python python programming"))*.