Fang, S., Chen, B., Tay, F. P., Ng, B. S., & Liu, D. X. (2007). An arginine-to-proline mutation in a domain with undefined functions within the helicase protein (Nsp13) is lethal to the coronavirus infectious bronchitis virus in cultured cells. Virology.

Fang, Shouguo, Bo Chen, Felicia P.L Tay, Beng Sern Ng, and Ding Xing Liu. "An Arginine-to-proline Mutation in a Domain With Undefined Functions Within the Helicase Protein (Nsp13) Is Lethal to the Coronavirus Infectious Bronchitis Virus in Cultured Cells." Virology 2007.

Fang, Shouguo, et al. "An Arginine-to-proline Mutation in a Domain With Undefined Functions Within the Helicase Protein (Nsp13) Is Lethal to the Coronavirus Infectious Bronchitis Virus in Cultured Cells." Virology 2007.