Perhaps you should try some spelling variations:
"dong toan hoc snippets" » "dung toan hoc snippets", "bong toan hoc snippets", "cong toan hoc snippets", "dong toan khoa snippets", "dong van hoc snippets", "dong hoa 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: (((("dong toan 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: (((("dong toan hoc snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dong toan hoc snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong toan hoc snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.