Perhaps you should try some spelling variations:
"dung dat viet snippets" » "dung dao viet snippets", "dung da viet snippets", "dung dai viet snippets", "dung va viet snippets", "dung tai viet snippets", "dung dat viet slippers"
"using a code snippets" » "using a core snippets", "using a code slippers"
"locating bug code snippets" » "locating bug core snippets", "locating bug code slippers", "locating bung code snippets", "locating bugs code 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: (((("using a code snippets") or ("dung dat viet snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using a code snippets") OR ("dung dat viet snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using a code snippets ) or ( dung dat viet snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using a code snippets") or ("dung dat viet snippets"))) or ("locating bug code snippets"))*.