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