Perhaps you should try some spelling variations:
"dung duc dan snippets" » "duong duc dan snippets", "dang duc dan snippets", "dung du dan snippets", "dung duoc dan snippets", "dung duc tan snippets", "dung duc dai snippets", "dung duc dan slippers"
"using _ code snippets" » "using _ code slippers"
"locating bug code 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 _ code snippets") or ("dung duc dan snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using _ code snippets") OR ("dung duc dan snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using _ code snippets ) or ( dung duc dan snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using _ code snippets") or ("dung duc dan snippets"))) or ("locating bug code snippets"))*.