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