Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"sach van toi snippets" » "sach han toi snippets", "sach va toi snippets", "bach van toi snippets", "sach van tai snippets", "sach van thi snippets", "sach van 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 van toi 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 van toi snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( sach van toi snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("sach van toi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.