A large group of the regiment arrives in Beidahuang. [Photo provided to China Daily]

Although there are already hundreds of books published on this subject, Zhu wanted to do it in a different way.

"Of course, I first thought of the place I went to as a zhiqing, Yuci, Shanxi province, but it is not easy to tell the stories of those youths to represent the whole picture of a specific group because those zhiqing's stories are more individual. The zhiqing in the Heilongjiang regiment were different because they lived a collective life in a half-militarized organization. They were also far larger in numbers," says Zhu.

Zhu worked with some zhiqing transferred from the Heilongjiang regiment when he went to Yuci for the second time. He found the "regiment zhiqing" were very different from the other ones. They were more obedient and tougher and had a stronger sense of collective identity. He became an observer of the regiment after spending time with its members, he says.

After the "cultural revolution" ended, Zhu found many novels and TV series centered on the zhiqing, but the most influential and powerful works were about the Heilongjiang Construction Regiment.

"The countryside in Yuci is not comparable to Beidahuang in terms of size of land, the number of people, or the scale of production. But I think it is easier to summarize the stories of the regiment according to different themes because it was a half-militarized unit, having a unified management," Zhu writes in postscript of the book.

"The difference between writing about the zhiqing in the Heilongjiang regiment and in places like Yuci is like the difference between writing the history of the battles of a field army and that of a guerrilla group in a certain province," he writes.