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