Perhaps you should try some spelling variations:
"dung nen doan snippets" » "dung nen dan snippets", "dung nen van snippets", "dung nen dat snippets", "dung nhan doan snippets", "dung ngan doan snippets", "dung tren doan snippets"
"using a code snippets" » "using a core snippets"
"locating bug code snippets" » "locating bug core snippets", "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 nen doan 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 nen doan snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using a code snippets ) or ( dung nen doan snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using a code snippets") or ("dung nen doan snippets"))) or ("locating bug code snippets"))*.