Perhaps you should try some spelling variations:
"locating bug core snippets" » "locating bug code snippets"
"van dung he snippets" » "van dung code snippets", "van dong he snippets", "xay dung he snippets", "tin dung he snippets", "van dung cho 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 dung he 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 dung he snippets") OR ("python using data snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( van dung he snippets ) or ( python using data snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van dung he snippets") or ("python using data snippets"))) or ("locating bug core snippets"))*.