Perhaps you should try some spelling variations:
"coder coder coupling study problem" » "coder mode coupling study problem" (Expand search), "coder model coupling study problem" (Expand search), "coder core coupling study problem" (Expand search), "coder coder coupling studies problem" (Expand search), "coder coder sampling study problem" (Expand search), "coder coder coupling state problem" (Expand search), "coder coder coupling student problem" (Expand search), "coder coder coupling body problem" (Expand search), "coder decoder coupling study problem" (Expand search), "code code coupling study problem" (Expand search), "decoder codec coupling study 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 coupling study problem") OR ("on python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder coupling study problem\") OR (\"on python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder coupling study problem ) OR ( on python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder coupling study problem") OR ("on python python python programming"))*.