The CCP newspaper report on this is… Interesting:

> Faced with such a "hard nut", Li Chengming strengthened his confidence: "In the war years, Communists were not afraid of death. This difficulty is nothing! We must do it! And we must do it beautifully!" Under the guidance of veteran experts, he led his team to fight for a thousand years. Over many days and nights, a set of nonlinear confidentiality processing technology for topographic maps suitable for national series of scales was developed.

https://archive.ph/20110804185923/http://cxzy.people.com.cn/...