Perhaps you should try some spelling variations:
"dung quang du snippets" » "dang quang du snippets", "luong quang du snippets", "dung luan du snippets", "dung quang duc snippets", "dung quang duy snippets", "dung quang cu 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: (((("dung quang du snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung quang du snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung quang du snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung quang du snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.