Perhaps you should try some spelling variations:
"dung hung code snippets" » "dung chung code snippets", "dung nhung code snippets", "dung huong code snippets", "dung hung code slippers"
"luan van code snippets" » "luan van de snippets", "luan van hoe snippets", "luan van cong snippets", "quan van code snippets", "lan van code snippets", "luan van 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: (((("luan van code snippets") or ("dung hung code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("luan van code snippets") OR ("dung hung code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( luan van code snippets ) or ( dung hung code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("luan van code snippets") or ("dung hung code snippets"))) or ("locating bug code snippets"))*.