These entries are queried from radb.net using whois, you can try my project getting these.
:AS54156 route: 198.135.74.0/24 descr: City of Huntsville origin: AS54156 remarks: Added by API Digital on behalf of City of Huntsville mnt-by: API-MNT changed: cadams [at] api-digital.com 20180810 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source