These entries are queried from radb.net using whois, you can try my project getting these.
:AS-MICROSOFT as-set: AS-MICROSOFT descr: Microsoft AS-SET members: AS3598, AS6584, AS8068, AS8070, AS8071, AS8073, AS8075 members: AS14413, AS20046, AS23468, AS62540, AS198015, AS198097 notify: radb [at] microsoft.com mnt-by: MAINT-MICROSOFT changed: mkasten [at] microsoft.com 20181126 source: ALTDB