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