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