Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van duc voi snippets" » "van duy voi snippets", "van du voi snippets", "tran duc voi snippets", "van duc loi snippets", "van dua voi snippets", "van duc vui snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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 duc voi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("van duc voi snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van duc voi snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van duc voi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.