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