These entries are queried from radb.net using whois, you can try my project getting these.
:AS-CLOUDFLARE as-set: AS-CLOUDFLARE descr: Cloudflare, Inc descr: 101 Townsend Street, San Francisco descr: California 94107, US descr: +1-650-319-8930 members: AS13335 members: AS13335:AS-CUSTOMERS members: AS14789 members: AS132892 members: AS133877 members: AS202623 members: AS209242 members: AS394536 remarks: --------------- remarks: Cloudflare announces its ASNs via many upstream ASNs remarks: All Cloudflare abuse reporting can be done via remarks: https://www.cloudflare.com/abuse remarks: --------------- mnt-by: MNT-CLOUD14 notify: rir [at] cloudflare.com changed: rir [at] cloudflare.com 20210324 source: ARIN