Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"sach tu toan snippets" » "sach thu toan snippets", "cach tu toan snippets", "sach ty toan snippets", "sach tu than snippets", "sach tap toan snippets", "sach duc 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: (((("sach tu 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: (((("sach tu toan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( sach tu toan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("sach tu toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.