pwr.wroc.pl has no NS records.
NS records for this zone are defined at wroc.pl.
NS records for this zone are defined at wroc.pl.
Question and response
Question
dig pwr.wroc.pl. NS
Answer
The response has no answer records.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0