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