3 ms·
The wikipedia article is lame, but there are images and a discussion here: https://blog.plover.com/aliens/dd/intro.html https://blog.plover.com/aliens/dd/intro
by lcuff 7y ago
The wikipedia article is lame, but there are images and a discussion here:
https://blog.plover.com/aliens/dd/intro.html https://blog.plover.com/aliens/dd/intro.html