Subnet Cheat Sheet – 24 Subnet Mask, 30, 26, 27, 29, and other IP Address CIDR Network References
Subnets – Learning IT
Finding the Subnet Mask on AIX – DataGeek.blog
You are designing a subnet mask for the 172.26.0.0 network. You want 26 subnets with up to 1800 hosts on each subnet. What subnet mask should you use? - Quora