Perhaps you should try some spelling variations:
"duong sach code snippets" » "duong manh code snippets", "duong sach che snippets", "duong sach de snippets", "duong sach code slippers"
"using a code snippets" » "using a code slippers"
"locating bug code snippets" » "locating bug code slippers", "locating bung code snippets", "locating bugs code snippets"

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

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