These entries are queried from radb.net using whois, you can try my project getting these.
:AS619 route: 163.251.121.0/24 descr: CenturyLink Proxy object remarks: to be deleted in March 2017 origin: AS619 notify: job [at] ntt.net mnt-by: MAINT-JOB changed: job [at] ntt.net 20160901 source: NTTCOM rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source