These entries are queried from radb.net using whois, you can try my project getting these.
:AS14757 route: 8.3.33.0/24 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040713 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 12.107.4.0/23 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 12.107.6.0/24 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 12.164.240.0/22 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 12.164.244.0/23 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 12.164.246.0/24 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 12.164.247.0/24 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 208.50.28.0/23 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 208.50.32.0/24 descr: DSW-US-BGP origin: AS14757 mnt-by: DSW-MNT changed: jspear [at] dsw.net 20040709 source: LEVEL3 rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source