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