1. Zhong Chenghua. China: CN 2060687u, 1990.
2. Zhong Chenghua. A new liquid-liquid mixer settler extractor. Proc. Int. Solvent Extraction Conf., Published for SCI by Elsevier Applied Science. New York, UK. 1993. 111.
3. Zhong Chenghua. Study of separated rare earth with a new mixer settler extractor. Proc. 3rd Int. Conf. on Rare Earth Development and Applications. Baotou, China. 1995. 766.
4. Zhong Chenghua. China: CN 2095706u, 1992.
5. Zhong Chenghua. Upper settler extractor: a new solvent extraction mixer settler. Proc. Int. Solvent Extraction Conf., Value Adding through Solvent Extraction, Vol.2, Melbourne, Australia. 1996. 1221.