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