Erratum. Issue 6 (9th July 2020) - Liu, Siwen; Li, Jian; Zhang, Yong; Liu, Na; Viljoen, Altus; Mostert, Diane; Zuo, Cunwu; Hu, Chunhua; Bi, Fangcheng; Gao, Huijun; Sheng, Ou; Deng, Guiming; et al.