Perhaps you should try some spelling variations:
"do duc chieu snippets" » "do duc code snippets", "do duc chien snippets", "do duc hieu snippets", "do doi chieu snippets", "dao duc chieu snippets", "do duy chieu snippets"
"locating bug core snippets" » "locating bug code snippets"
"python using data snippets" » "python using java snippets", "python using sat snippets", "python missing data snippets"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("do duc chieu snippets") or ("python using data snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("do duc chieu snippets") OR ("python using data snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( do duc chieu snippets ) or ( python using data snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("do duc chieu snippets") or ("python using data snippets"))) or ("locating bug core snippets"))*.