Perhaps you should try some spelling variations:
"dung java java snippets" » "dung va java snippets"
"hoc sach cac snippets" » "hoc sinh cac snippets", "hoc cac cac snippets", "hoc anh cac snippets", "hoc sach cap snippets", "hoc sach bac snippets", "hoc sach dao 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: (((("hoc sach cac snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("hoc sach cac snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( hoc sach cac snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("hoc sach cac snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.