Perhaps you should try some spelling variations:
"cong thanh he snippets" » "dong thanh he snippets", "cong trinh he snippets", "cong tan he snippets", "cong thanh hue snippets", "cong thanh ha snippets", "cong thanh ve 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: (((("cong thanh he snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("cong thanh he snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong thanh he snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong thanh he snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.