Perhaps you should try some spelling variations:
"sang sach thue snippets" » "mang sach thue snippets", "sang tac thue snippets", "ban sach thue snippets", "sang sach thu snippets", "sang sach thieu snippets", "sang sach tham snippets"
"dung java java snippets" » "dung 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: (((("sang sach thue snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("sang sach thue snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( sang sach thue snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("sang sach thue snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.