These entries are queried from radb.net using whois, you can try my project getting these.
:AS-AMAZON as-set: AS-AMAZON descr: Amazon ASNs members: AS-AMAZON-NA, AS-AMAZON-AP, AS-AMAZON-EU admin-c: AC6-ORG-ARIN tech-c: AC6-ORG-ARIN notify: noc [at] amazon.com mnt-by: MAINT-AS16509 changed: noc [at] amazon.com 20151027 #17:32:13Z source: RADB