Apex domains cannot have CNAME records.
Question and response
Question
dig internet.ee. NS
Answer
internet.ee. 5 NS x.tld.ee.
internet.ee. 5 NS e.tld.ee.
internet.ee. 5 NS b.tld.ee.
internet.ee. 5 NS c.tld.ee.
Authority
The response has no authority records.
Additional
b.tld.ee. 165804 A 194.146.106.110
e.tld.ee. 165804 A 204.61.216.36
b.tld.ee. 165804 AAAA 2001:67c:1010:28:0:0:0:53
e.tld.ee. 165804 AAAA 2001:678:94:53:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0