Perhaps you should try some spelling variations:
"dung loai hoc snippets" » "dung lai hoc snippets", "dang loai hoc snippets", "dung hoai hoc snippets", "dung logic hoc snippets", "dung loai khoa snippets", "dung dai hoc snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: (((("dung loai hoc snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung loai hoc snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung loai hoc snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung loai hoc snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.