Perhaps you should try some spelling variations:
"dung java java snippets" » "dung va java snippets"
"van tuan de snippets" » "van quan de snippets", "van ban de snippets", "anh tuan de snippets", "van tuan le snippets", "van luan de snippets", "van toan de 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 java java snippets") or ("van tuan de snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung java java snippets") OR ("van tuan de snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung java java snippets ) or ( van tuan de snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung java java snippets") or ("van tuan de snippets"))) or ("locating bug code snippets"))*.