Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"han du toan snippets" » "han duc toan snippets", "han du doan snippets", "han dung toan snippets", "han dau toan snippets", "van du toan snippets", "han tu toan 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: (((("han du toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("han du toan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( han du toan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("han du toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.