Perhaps you should try some spelling variations:
"hoc manh toan snippets" » "hoc thanh toan snippets", "hoc anh tuan snippets", "hoc tinh toan snippets", "hoc anh toan snippets", "hoc hanh toan snippets", "hoc danh toan 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: (((("hoc manh toan 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 manh toan snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( hoc manh toan snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("hoc manh toan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.