These entries are queried from radb.net using whois, you can try my project getting these.
:AS137456 route: 103.108.252.0/24 origin: AS137456 descr: BHP BILLITON IRON ORE PTY. LTD. 125 St. Georges Terrace mnt-by: MAINT-BBIOPL-AU last-modified: 2018-11-02T01:36:16Z source: APNIC rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source