Perhaps you should try some spelling variations:
"dung nhat toan snippets" » "dung nhat code snippets", "dung nhan toan snippets", "dang nhat toan snippets", "dung nha toan snippets", "dung nhat tan snippets", "dung thuat toan snippets", "dung nhat trang snippets"
"locating bug core snippets" » "locating bug code snippets"
"hang java java snippets" » "hang va java 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: (((("hang java java snippets") or ("dung nhat toan snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("hang java java snippets") OR ("dung nhat toan snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( hang java java snippets ) or ( dung nhat toan snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("hang java java snippets") or ("dung nhat toan snippets"))) or ("locating bug core snippets"))*.