These entries are queried from radb.net using whois, you can try my project getting these.
:AS5538 route: 5.152.224.0/21 descr: LUMII origin: AS5538 mnt-by: lumii-mnt created: 2012-07-24T06:36:10Z last-modified: 2012-07-24T06:36:10Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid route: 85.254.192.0/18 descr: SigmaNet-Geant origin: AS5538 notify: dc [at] sigmanet.lv mnt-by: LUMII-MNT created: 2005-02-15T08:09:11Z last-modified: 2010-07-15T13:34:33Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid route: 92.240.64.0/19 descr: LU MII origin: AS5538 mnt-by: lumii-mnt created: 2007-11-20T12:09:37Z last-modified: 2019-10-01T06:00:51Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid route: 185.23.160.0/22 descr: SigmaNet-Geant origin: AS5538 mnt-by: LUMII-MNT created: 2015-10-12T06:48:58Z last-modified: 2015-10-12T06:48:58Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid route: 194.8.1.0/24 descr: LUMII origin: AS5538 notify: dc [at] sigmanet.lv mnt-by: lumii-mnt created: 2017-04-10T08:47:23Z last-modified: 2017-04-10T08:47:23Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid route: 194.8.2.0/23 descr: LUMII origin: AS5538 mnt-by: lumii-mnt created: 2017-04-10T08:44:44Z last-modified: 2020-01-21T08:40:42Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route6: 2a02:500::/29 descr: Institute of Mathematics and Computer Science origin: AS5538 mnt-by: LUMII-MNT created: 2019-06-19T08:59:02Z last-modified: 2019-06-19T08:59:02Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid route6: 2a02:500::/32 descr: Institute of Mathematics and Computer Science of University of Latvia origin: AS5538 mnt-by: LUMII-MNT created: 2009-02-12T10:15:48Z last-modified: 2009-02-12T10:15:48Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid route6: 2a02:500:4000::/35 descr: SigmaNet NIC origin: AS5538 mnt-by: LUMII-MNT created: 2015-10-16T09:16:44Z last-modified: 2015-10-16T09:16:44Z source: RIPE remarks: **************************** remarks: * THIS OBJECT IS MODIFIED remarks: * Please note that all data that is generally regarded as personal remarks: * data has been removed from this object. remarks: * To view the original object, please query the RIPE Database at: remarks: * http://www.ripe.net/whois remarks: **************************** rpki-ov-state: valid