Perhaps you should try some spelling variations:
"tran tong luan snippets" » "tran trong luan snippets", "tran thong luan snippets", "tran tuong luan snippets", "tran tang luan snippets", "tran dung luan snippets", "tran hang luan snippets", "tran tong luan slippers"
"dung java java snippets" » "dung va java snippets", "dung 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.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"tran tong luan snippets\") OR (\"dung java java snippets\"))) OR (\"locating bug code snippets\"))~".
• Removing quotes may allow a broader search: (((( tran tong luan snippets ) OR ( dung java java snippets ))) OR ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("tran tong luan snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets"))*.