Perhaps you should try some spelling variations:
"using while using sampling error" » "using while using subsampling error" (Expand search), "using while using saline error" (Expand search), "using while using samples error" (Expand search), "using while using sampling effort" (Expand search), "using whole using sampling error" (Expand search), "using white using sampling error" (Expand search), "casing while using sampling error" (Expand search)
"using coding python python programming" » "using codigo python python programming" (Expand search), "using codigos python python programming" (Expand search), "using using python python programming" (Expand search), "using coding pythons python programming" (Expand search), "using coding piton python programming" (Expand search), "using coding pitons python programming" (Expand search), "using coping python python programming" (Expand search), "using coating python python programming" (Expand search), "using cooking python 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: (("using while using sampling error") OR ("using coding python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"using while using sampling error\") OR (\"using coding python python programming\"))".
• Removing quotes may allow a broader search: (( using while using sampling error ) OR ( using coding python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("using while using sampling error") OR ("using coding python python programming"))*.