Perhaps you should try some spelling variations:
"duong minh code snippets" » "duong manh code snippets", "truong minh code snippets", "thong minh code snippets", "duong minh cong snippets", "duong minh de snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug code slippers" » "locating bung code slippers", "locating bugs code slippers"

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 java java snippets") or ("duong minh code snippets"))) or ("locating bug code slippers"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung java java snippets") OR ("duong minh code snippets"))) OR ("locating bug code slippers")).
• Removing quotes may allow a broader search: (((( dung java java snippets ) or ( duong minh code snippets ))) or ( locating bug code slippers )).
• Adding a wildcard symbol may retrieve word variants: (((("dung java java snippets") or ("duong minh code snippets"))) or ("locating bug code slippers"))*.