Perhaps you should try some spelling variations:
"code to precoder detection problem" » "code to precoder selection problem" (Expand search), "code to order detection problem" (Expand search), "code to code detection problem" (Expand search), "code to precoder detection program" (Expand search), "code to precoder demarcation problem" (Expand search), "code mimo precoder detection problem" (Expand search), "code to precedent detection problem" (Expand search)
"api python python python programming" » "api pythons python python programming" (Expand search), "api piton python python programming" (Expand search), "api pitons python python programming" (Expand search), "rpa python 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: "((\"code to precoder detection problem\") OR (\"api python python python programming\"))~".
• Removing quotes may allow a broader search: (( code to precoder detection problem ) OR ( api python python python programming ))~.
• Adding a wildcard symbol may retrieve word variants: (("code to precoder detection problem") OR ("api python python python programming"))*.