Perhaps you should try some spelling variations:
"dung truong cao snippets" » "duong truong cao snippets", "dung trong cao snippets", "dung trung cao snippets", "dung truong dai snippets"
"hang java java snippets" » "hang 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: (((("hang java java snippets") or ("dung truong cao snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("hang java java snippets") OR ("dung truong cao snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( hang java java snippets ) or ( dung truong cao snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("hang java java snippets") or ("dung truong cao snippets"))) or ("locating bug code snippets"))*.