Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"viet duy doc snippets" » "viet duc doc snippets", "viet dung doc snippets", "viet tu doc snippets", "viet day doc snippets", "viet duy dac snippets", "viet duy dot 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: (((("viet duy doc snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("viet duy doc snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( viet duy doc snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("viet duy doc snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.