Perhaps you should try some spelling variations:
"dung thi chap snippets" » "dung thi code snippets", "dung tai chap snippets", "dung tri chap snippets", "dung chi chap snippets", "dung thi phap snippets", "dung thi cham snippets", "dung thi cap snippets"
"locating bug core snippets" » "locating bug code snippets"
"dung java java snippets" » "dung va java 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 thi chap snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung thi chap snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( dung thi chap snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung thi chap snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.