Perhaps you should try some spelling variations:
"va duong luan snippets" » "va dung luan snippets", "va dong luan snippets", "va duong quan snippets", "van duong luan snippets", "va tuong luan snippets", "va huong luan snippets", "va duong luan slippers"
"using java java snippets" » "using data java snippets", "using java java slippers"
"locating bug code snippets" » "locating bug code slippers", "locating bung code snippets", "locating bugs code snippets", "locating bug core snippets"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("va duong luan snippets") or ("using java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("va duong luan snippets") OR ("using java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( va duong luan snippets ) or ( using java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("va duong luan snippets") or ("using java java snippets"))) or ("locating bug code snippets"))*.