These entries are queried from radb.net using whois, you can try my project getting these.
:AS21984 route: 151.188.0.0/16 descr: Fairfax County Public Schools 151.188.0.0/16 route origin: AS21984 mnt-by: MNT-FCPS changed: christopher.gerber [at] level3.com 20050726 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 151.188.0.0/16 descr: Comcast Cable Communications, Inc. 1800 Bishops Gate Blvd Mt Laurel, NJ 08054 origin: AS21984 remarks: Proxy add for customer Fairfax County Public Schools mnt-by: MAINT-AS7922 changed: chris_johnson8 [at] cable.comcast.com 20140806 source: RADB last-modified: 2023-11-13T15:54:10Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 151.188.0.0/18 origin: AS21984 descr: MRFD #ECR000001350769 remarks: Proxy object for AS21984 mnt-by: MAINT-AS22773 changed: cciatl-nocengineer [at] cox.com 20220520 source: RADB last-modified: 2023-11-13T16:11:18Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 151.188.128.0/18 origin: AS21984 descr: MRFD #ECR000001350769 remarks: Proxy object for AS21984 mnt-by: MAINT-AS22773 changed: cciatl-nocengineer [at] cox.com 20220520 source: RADB last-modified: 2023-11-13T16:11:18Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 151.188.192.0/18 origin: AS21984 descr: MRFD #ECR000001350769 remarks: Proxy object for AS21984 mnt-by: MAINT-AS22773 changed: cciatl-nocengineer [at] cox.com 20220520 source: RADB last-modified: 2023-11-13T16:11:18Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source