These entries are queried from radb.net using whois, you can try my project getting these.
:AS-TWITTER as-set: AS-TWITTER descr: Twitter members: AS13414, AS35995, AS54888, AS63179, AS-CRASHLYTICS admin-c: NETWO3685-ARIN tech-c: NETWO3685-ARIN notify: noc [at] twitter.com mnt-by: MAINT-AS13414 changed: caw [at] twitter.com 20150401 #01:16:24Z source: RADB