This site now hosts a complete archive of PDF versions of The Problemist Supplement, from 1992 to the current year. This magazine is aimed mainly at newcomers to chess composition, so it is recommended for those who want to find out more about chess problems. You can find the archive here.
It has been a few weeks since we last had a selfmate, so here is one by the composer
who is generally regarded as just about the world leader in this genre. The bQ
battery along the 6th rank is clearly going to be utilised somehow, but exactly how?
Not an easy solve, but I am sure you can get there with a bit of diligence!
The key is 1.Sc2! This undefends the square f5, thus creating the threat 2.Rf5+
Kxf5+ 3.Bg6+ Qxg6#.
Black’s queen is unable to get off the 6th rank, but he can defend by closing
the rank with one of his minor pieces. However, all three options allow White to
force a double check and mate, by a different move of his Rg5: