Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van viet du snippets" » "san viet du snippets", "gian viet du snippets", "tran viet du snippets", "van viet duc snippets", "van viet duy snippets", "van viet tu 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 viet du 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 viet du snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van viet du snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van viet du snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.