Perhaps you should try some spelling variations:
"coder decoder precoder sample problem" » "coder encoder decoder sample problem" (Expand search), "coder decoder codec sample problem" (Expand search), "coder decoder precoder complex problem" (Expand search), "coder decoder precoder same problems" (Expand search), "encoder decoder precoder sample problem" (Expand search)
"_ python python python programming" » "_ pythons python python programming" (Expand search), "_ piton python python programming" (Expand search), "_ pitons python python programming" (Expand search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder decoder precoder sample problem\") OR (\"_ python python python programming\"))~".
• Removing quotes may allow a broader search: (( coder decoder precoder sample problem ) OR ( _ python python python programming ))~.
• Adding a wildcard symbol may retrieve word variants: (("coder decoder precoder sample problem") OR ("_ python python python programming"))*.