Perhaps you should try some spelling variations:
"han quoc code snippets" » "han quoc co snippets", "han quoc cong snippets", "phan quoc code snippets", "nhan quoc code snippets", "hanh quoc code snippets", "han quoc code slippers"
"dung java java snippets" » "dung va java snippets", "dung java java slippers"
"locating bug code snippets" » "locating bug code slippers", "locating bung code snippets", "locating bugs code 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: (((("han quoc code snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("han quoc code snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( han quoc code snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("han quoc code snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.