These entries are queried from radb.net using whois, you can try my project getting these.
:AS18624 route: 8.15.172.0/23 descr: Customer Route origin: AS18624 mnt-by: COW-MNT changed: venkata.chivukula [at] level3.com 20081107 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 8.15.174.0/23 descr: EMBARQ HSD origin: AS18624 mnt-by: EMBARQ-MNT changed: a.elamparuthi [at] level3.com 20081107 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 8.15.176.0/21 descr: Customer Route origin: AS18624 mnt-by: COW-MNT changed: steve.musser [at] level3.com 20080502 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 8.15.184.0/21 descr: EMBARQ HSD origin: AS18624 mnt-by: EMBARQ-MNT changed: modi.kalpesh [at] level3.com 20090106 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 8.15.228.64/26 descr: City of Wilson route origin: AS18624 mnt-by: COW-MNT changed: kristopher.harig [at] level3.com 20070702 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 8.15.254.0/24 descr: new block origin: AS18624 mnt-by: COW-MNT changed: james.lara [at] level3.com 20080410 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 66.251.214.0/24 descr: creating route origin: AS18624 mnt-by: COW-MNT changed: will.mcbryde [at] level3.com 20070330 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 152.26.63.0/24 descr: ticket4474400 origin: AS18624 mnt-by: COW-MNT changed: nicholas.etnoyer [at] level3.com 20101118 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 162.254.88.0/23 descr: Ticket8051406 origin: AS18624 mnt-by: COW-MNT changed: danial.brown [at] level3.com 20140625 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 162.254.90.0/23 descr: adding route origin: AS18624 mnt-by: COW-MNT changed: brynn.howe [at] level3.com 20180113 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 173.209.176.0/20 descr: CITY OF WILSON origin: AS18624 mnt-by: COW-MNT changed: angela.barentine [at] level3.com 20120521 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 208.6.83.0/24 descr: EMBARQ HSD origin: AS18624 mnt-by: EMBARQ-MNT changed: tom.mueller [at] embarq.com 20071221 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.152.0.0/20 descr: creating route origin: AS18624 mnt-by: COW-MNT changed: oluseyi.adeniran [at] level3.com 20090319 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.152.0.0/24 descr: creating route origin: AS18624 mnt-by: COW-MNT changed: oluseyi.adeniran [at] level3.com 20090319 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.152.1.0/24 descr: creating route origin: AS18624 mnt-by: COW-MNT changed: oluseyi.adeniran [at] level3.com 20090319 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.152.2.0/23 descr: creating route origin: AS18624 mnt-by: COW-MNT changed: oluseyi.adeniran [at] level3.com 20090319 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.152.4.0/22 descr: creating route origin: AS18624 mnt-by: COW-MNT changed: oluseyi.adeniran [at] level3.com 20090319 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.152.8.0/21 descr: creating route origin: AS18624 mnt-by: COW-MNT changed: oluseyi.adeniran [at] level3.com 20090319 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.210.64.0/20 descr: Ticket3630103 origin: AS18624 mnt-by: COW-MNT changed: royer.rob [at] level3.com 20090904 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.210.80.0/22 descr: 4041801 origin: AS18624 mnt-by: COW-MNT changed: barry.wahrmann [at] level3.com 20100415 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.210.84.0/22 descr: 4041801 origin: AS18624 mnt-by: COW-MNT changed: barry.wahrmann [at] level3.com 20100415 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.210.88.0/21 descr: 4041801 origin: AS18624 mnt-by: COW-MNT changed: barry.wahrmann [at] level3.com 20100415 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source