These entries are queried from radb.net using whois, you can try my project getting these.
:AS-PUREVOLTAGE as-set: AS-PUREVOLTAGE descr: AS macro for Pure Voltage members: AS26548,AS58305,AS46487,AS397423 notify: ip-admin [at] purevoltage.net mnt-by: MNT-PE-99 changed: ip-admin [at] purevoltage.net 20190613 source: ARIN