Perhaps you should try some spelling variations:
"thi van nghe snippets" » "thi van code snippets", "thi lan nghe snippets", "thi hanh nghe snippets", "thi nang nghe 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: (((("thi van nghe snippets") or ("python using data snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("thi van nghe snippets") OR ("python using data snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( thi van nghe snippets ) or ( python using data snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("thi van nghe snippets") or ("python using data snippets"))) or ("locating bug core snippets"))*.