1. Hunter D. Papermaking: the history and technique of an ancient craft. New York: Dover Publications; 1978. p. 496.
2. Wang JH. The history of papermaking engineering and technology in ancient China. Taiyuan: Shanxi Education Press; 2006. p. 255 (in Chinese).
3. Yang ZH. The investigation and restoration of tiē luò of fú wàng gé: a case study of the writings by emperor qianlong in fú wàng gé (tower of elusive dreams). Palace Museum J. 2015;3:136–62 (in Chinese).
4. Zhao EX. Qing shi gao. Beijing: Zhonghua shuju; 1977. p. 11574 (in Chinese).
5. Van Beek HCA, Heertjes PM. Fading by light of organic dyes on textiles and other materials. Stud Conserv. 1966;11(3):123–32.