Perhaps you should try some spelling variations:
"van viet code snippets" » "van viet co snippets", "van viet some snippets", "san viet code snippets", "gian viet code snippets", "tran viet code snippets", "van viet code slippers"
"dung cong code snippets" » "dung trong code snippets", "dung cong cong snippets", "dung cong co snippets", "dung cong che snippets", "dung cong code slippers"
"locating bug code snippets" » "locating bug code slippers", "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: (((("van viet code snippets") or ("dung cong code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("van viet code snippets") OR ("dung cong code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van viet code snippets ) or ( dung cong code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van viet code snippets") or ("dung cong code snippets"))) or ("locating bug code snippets"))*.