Perhaps you should try some spelling variations:
"dong viet cau snippets" » "cong viet cau snippets", "dung viet cau snippets", "dang viet cau snippets", "dong viet chau snippets", "dong viet ca snippets", "dong viet chu snippets"
"using a code snippets" » "using a core snippets"
"locating bug code snippets" » "locating bug core snippets", "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: (((("using a code snippets") or ("dong viet cau snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using a code snippets") OR ("dong viet cau snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using a code snippets ) or ( dong viet cau snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using a code snippets") or ("dong viet cau snippets"))) or ("locating bug code snippets"))*.