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