pbs.view21.net has no NS records.
NS records for this zone are defined at view21.net.
NS records for this zone are defined at view21.net.
Question and response
Question
dig pbs.view21.net. NS
Answer
The response has no answer records.
Authority
view21.net. 900 SOA ns-1957.awsdns-52.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0