Perhaps you should try some spelling variations:
"coder coder complex hard problem" » "coder copper complex hard problem" (Expand search), "coder holder complex hard problem" (Expand search), "coder modern complex hard problem" (Expand search), "coder coder complex and problem" (Expand search), "coder coder complex has problem" (Expand search), "coder coder complex hr problem" (Expand search), "coder coder complex old problem" (Expand search), "coder decoder complex hard problem" (Expand search), "code code complex hard problem" (Expand search), "decoder codec complex hard 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 complex hard problem") OR ("on python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder complex hard problem\") OR (\"on python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder complex hard problem ) OR ( on python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder complex hard problem") OR ("on python python python programming"))*.