These entries are queried from radb.net using whois, you can try my project getting these.
:AS23983 route: 203.237.128.0/20 descr: Daejeon University origin: AS23983 mnt-by: MAINT-AS4766 changed: jacob [at] kornet.net 20040129 source: RADB last-modified: 2023-11-13T16:15:43Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 203.237.144.0/21 descr: Daejeon University origin: AS23983 mnt-by: MAINT-AS4766 changed: jacob [at] kornet.net 20040129 source: RADB last-modified: 2023-11-13T16:15:43Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 203.237.152.0/23 descr: Daejeon University origin: AS23983 mnt-by: MAINT-AS4766 changed: driftey [at] kornet.net 20040827 source: RADB last-modified: 2023-11-13T16:15:43Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source