Perhaps you should try some spelling variations:
"dung van hoan snippets" » "dung van hoang snippets", "dung van hoa snippets", "dung van toan snippets", "duong van hoan snippets", "dung va hoan snippets", "dang van hoan 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 ("dung van hoan snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using a code snippets") OR ("dung van hoan snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using a code snippets ) or ( dung van hoan snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using a code snippets") or ("dung van hoan snippets"))) or ("locating bug code snippets"))*.