In the Qin Dynasty, about 210 BC, one of the emperors had a whole army of men made out of clay to go in his tomb and guard him in the afterlife. Each one was just a little bit different from all the others: some had shorter hair, while others had longer hair. Some had wide noses, and others had narrow noses.
To make a head like the ones the emperor buried in his tomb, build it out of clay. It will use less clay if you make an armature. That’s a core made out of something else. You might use a balloon as your armature, or crumple paper into balls and then cover them with tape.
Art in China (Oxford History of Art Series), by Craig Clunas (1997). Not specifically , but a good introduction to the spirit of Chinese art. Warning: this one is not arranged in chronological order. Instead, it has chapters on sculpture, calligraphy, and so on.
The Incredible Story of China’s Buried Warriors, by Dorothy Hinshaw Patent (1999). For middle schoolers, about the terracotta army figures shown on this page. Great reviews!