Apex domains cannot have CNAME records.
Question and response
Question
dig voiceworks.nl. NS
Answer
voiceworks.nl. 5 NS sri.ns.cloudflare.com.
voiceworks.nl. 5 NS liz.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0