ptr-mx0.doct.org.ua has no NS records.
NS records for this zone are defined at doct.org.ua.
NS records for this zone are defined at doct.org.ua.
Question and response
Question
dig ptr-mx0.doct.org.ua. NS
Answer
The response has no answer records.
Authority
doct.org.ua. 3600 SOA ns.doct.org.ua. hostmaster.doct.org.ua. 2014091133 3600 900 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0