If your DNS is hosted by TornevallNET and need to point out a specific amount of nameservers, this is the page you should look at.
Recursive DNS cluster
DNS-Servers marked with PARTIALLY RECURSIVE is, as said, partially recursive. By means, chosen networks - mostly located in Sweden - are allowed to use them as they normally use servers like 18.104.22.168, 22.214.171.124, 126.96.36.199, etc.
If you feel this doesn't work for you, you can see the current permission list at https://auth.tornevall.net/dns-recursion.txt and contact email@example.com if you feel that you want to be included in the recursion permissions.
There are more servers like below, that allows recursion but those are the publicly maintained list.
188.8.131.52, or the IPv6-filtered all-recursion DNS has been removed since Netflix now allows local tunnels (partially).