These entries are queried from radb.net using whois, you can try my project getting these.
:AS-SO-NET as-set: AS-SO-NET descr: ASes routed by So-net members: AS2527, AS9600, AS9619, AS24278, AS131930 admin-c: JP00019611 tech-c: JP00019611 notify: noc [at] so-net.ne.jp mnt-by: MAINT-AS2527 changed: noc [at] so-net.ne.jp 20181019 source: NTTCOM as-set: AS-SO-NET descr: ASes routed by So-net members: AS2527, AS9600, AS9619, AS24278, AS131930 admin-c: JP00019611 tech-c: JP00019611 notify: noc [at] so-net.ne.jp mnt-by: MAINT-AS2527 changed: noc [at] so-net.ne.jp 20240404 source: JPIRR as-set: AS-SO-NET descr: ASes routed by So-net members: AS2527, AS9600, AS9619, AS24278, AS131930 admin-c: JP00019611 tech-c: JP00019611 notify: noc [at] so-net.ne.jp mnt-by: MAINT-AS2527 changed: noc [at] so-net.ne.jp 20230629 source: RADB last-modified: 2023-11-13T16:17:32Z