Perhaps you should try some spelling variations:
"dung tinh doc snippets" » "dang tinh doc snippets", "dung ninh doc snippets", "dung tin doc snippets", "dung trinh doc snippets", "dung tinh hoc snippets", "dung tinh doi snippets"
"hang java java snippets" » "hang 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 tinh doc snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung tinh doc snippets") OR ("hang java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung tinh doc snippets ) or ( hang java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung tinh doc snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))*.