Perhaps you should try some spelling variations:
"phung thi doan snippets" » "huong thi doan snippets", "phung ho doan snippets", "phung thai doan snippets", "phung thi hoan snippets", "phung thi loan 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: (((("phung thi doan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("phung thi doan snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( phung thi doan snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("phung thi doan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.