Encyclopedia of Life and Death
The problems are divided into five categories:
- Beginner (200 problems)
- Elementary (922 problems)
- Intermediate (935 problems)
- Advanced (793 problems)
- Strange and unusual positions (28 problems)
The Elementary level problems include problem 405.
- Ulrich Goertz: In my opinion this is a great resource for players of almost all levels. The user interface is a bit outdated, though, so people may want to translate the problems into SGF format. Bill Shubert has written a tool which does this: cho2sgf (this is the source code in C, and should be easy to use on Unix systems). I have translated this into Python: cho2sgf.py; to use this version, you need to have Python installed. The problems can then be used with Uligo, for example. 
- bocephus: I have this and find it a wonderful resource, especially combined with Uligo. The MS-DOS part of the program doesn't work on my XP or Server 2000 boxes. It did work under an old 98 box. Luckily, you don't need a working install to run the script to convert for Uligo usage. Now if I can figure out how to get Uligo working for my Clie, I'll be all set.
- pc: You can run this old DOS program on most machines if you get the DOS emulator: dosbox. You can download dosbox off the web. I carry the program around on a memory stick and can use it on a multitude of machines, new and old.
 There might be an error within the cho2sgf.py program. It only creates the abc files, and not the s1 and s2. These have another 228 problems. (28 advanced in s1 and 200 beginner problems). You just need to tweak a little bit the source code in python and you have the original program. Search for this line:
problemCollection = 'abc'
and just replace abc with s1 (for rare problems) or s2 (for beginner problems)