These entries are queried from radb.net using whois, you can try my project getting these.
:AS53897 route: 199.187.144.0/22 descr: Prolexic Technologies, Inc. origin: AS53897 mnt-by: MAINT-AS32787 notify: hostmaster [at] prolexic.com changed: vwilliams [at] prolexic.com 20141108 source: RADB last-modified: 2023-11-13T16:13:32Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 199.187.146.0/24 descr: IBM BCRS origin: AS53897 mnt-by: MAINT-AS27506 changed: mahmed [at] lightower.com 20140713 source: RADB last-modified: 2023-11-13T15:46:36Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source