Perhaps you should try some spelling variations:
"van thinh doc snippets" » "van thanh doc snippets", "van chinh doc snippets", "van minh doc snippets", "van trinh doc snippets", "van thinh duc snippets", "van thinh doan 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 thinh doc 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 thinh doc snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van thinh doc snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van thinh doc snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.