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