Perhaps you should try some spelling variations:
"dung van hoat snippets" » "duong van hoat snippets", "dang van hoat snippets", "dung von hoat snippets", "dung van hoa snippets", "dung van hoan snippets", "dung dan hoat snippets"
"dung va java snippets" » "dung java java 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: (((("dung va java snippets") or ("dung van hoat snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung va java snippets") OR ("dung van hoat snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung va java snippets ) or ( dung van hoat snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung va java snippets") or ("dung van hoat snippets"))) or ("locating bug code snippets"))*.