Perhaps you should try some spelling variations:
"dung cong code snippets" » "dung trong code snippets", "dung cong cong snippets", "dung cong co snippets", "dung cong che snippets", "dung cong code slippers"
"van hoc code snippets" » "van hoc co snippets", "van hoc cong snippets", "van hoc de snippets", "van hoa code snippets", "van hoc 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 hoc 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 hoc code snippets") OR ("dung cong code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van hoc code snippets ) or ( dung cong code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van hoc code snippets") or ("dung cong code snippets"))) or ("locating bug code snippets"))*.