Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"duc dan toan snippets" » "duc van toan snippets", "duc dan than snippets", "duc manh toan snippets", "duoc dan toan snippets", "duc tan toan snippets", "duc dai 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: (((("duc dan 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: (((("duc dan toan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duc dan toan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duc dan toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.