Perhaps you should try some spelling variations:
"coder coder control testing problem" » "coder coder control test problem" (Expand search), "coder coder control training problem" (Expand search), "coder coder control nesting problem" (Expand search), "coder coder control nesting problems" (Expand search), "coder coder control teaching problem" (Expand search), "coder poder control testing problem" (Expand search), "coder encoder control testing problem" (Expand search), "coder poder controle testing problem" (Expand search), "coder decoder control testing problem" (Expand search), "code code control testing problem" (Expand search), "decoder codec control testing 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 control testing problem") OR ("on python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder control testing problem\") OR (\"on python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder control testing problem ) OR ( on python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder control testing problem") OR ("on python python python programming"))*.