These entries are queried from radb.net using whois, you can try my project getting these.
:AS53504 route: 199.255.168.0/21 descr: PulseNet origin: AS53504 mnt-by: MAINT-AS27506 changed: rhinst [at] lightower.com 20160902 #18:57:08Z source: RADB last-modified: 2023-11-13T15:49:51Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source