Upside-down and mirror looking magic square
of order 4 with magic sum 88 published by
Macau Post Office, China.
- Alex Bellos, Science and Mathematics, Macau’s magic square stamps just made philately even more nerdy, https://www.theguardian.com/science/alexs-adventures-innumberland/2014/nov/04/macaus-magic-square-stamps-just-made-philately-even-more-nerdy