These entries are queried from radb.net using whois, you can try my project getting these.
:AS13925 route: 23.131.160.0/24 descr: Null Route Networks - v4 origin: AS13925 mnt-by: MNT-VHNS changed: nigel [at] nullroutenetworks.com 20180723 source: ARIN rpki-ov-state: valid route: 23.131.160.0/24 descr: Null Route Networks - v4 origin: AS13925 mnt-by: MAINT-AS13925 changed: nigel [at] nullroutenetworks.com 20220404 source: ALTDB rpki-ov-state: valid route: 23.131.161.0/24 descr: Null Route Networks - v4 - 2 origin: AS13925 mnt-by: MAINT-AS13925 changed: nigel [at] nullroutenetworks.com 20220404 source: ALTDB rpki-ov-state: valid route: 23.131.161.0/24 descr: Null Route Networks - v4 - 2 origin: AS13925 mnt-by: MNT-VHNS changed: nigel [at] nullroutenetworks.com 20191119 source: ARIN rpki-ov-state: valid route: 44.4.64.0/22 descr: Null Route Networks - Customer 1001 - v4 origin: AS13925 mnt-by: MAINT-AS13925 changed: nigel [at] nullroutenetworks.com 20220404 source: ALTDB rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route6: 2001:470:f6::/48 descr: Null Route Networks - v6 origin: AS13925 mnt-by: MAINT-AS13925 changed: nigel [at] nullroutenetworks.com 20220404 source: ALTDB rpki-ov-state: valid route6: 2001:470:f6::/48 origin: AS13925 descr: NET-2001-470-f6---48-AS13925 admin-c: ZH17-ARIN tech-c: ZH17-ARIN mnt-by: MNT-HURC source: ARIN created: 2022-01-20T20:20:09Z last-modified: 2022-01-20T20:20:09Z rpki-ov-state: valid route6: 2620:138:5000::/44 descr: Null Route Networks - v6 origin: AS13925 mnt-by: MAINT-AS13925 changed: nigel [at] nullroutenetworks.com 20220404 source: ALTDB rpki-ov-state: valid route6: 2620:138:5000::/44 descr: Null Route Networks - v6 origin: AS13925 mnt-by: MNT-VHNS changed: nigel [at] nullroutenetworks.com 20180723 source: ARIN rpki-ov-state: valid route6: 2620:138:5002::/48 descr: Vultr Customer Route origin: AS13925 notify: network [at] choopa.com mnt-by: MAINT-AS20473 changed: network [at] choopa.com 20240226 #12:34:18-18000 source: RADB last-modified: 2024-02-26T17:36:30Z rpki-ov-state: valid