Perhaps you should try some spelling variations:
"van hoang cao snippets" » "van hoan cao snippets", "quan hoang cao snippets", "tran hoang cao snippets", "van hoang bao snippets", "van hoang hao snippets", "van hoang thao snippets"
"dung java java snippets" » "dung va 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: (((("van hoang cao 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 hoang cao snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van hoang cao snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van hoang cao snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.