1. Emergence of a novel coronavirus causing respiratory illness from Wuhan, China;Tang;J Infect,2020
2. Wuhan coronavirus outbreak.2 February 2020. https://www.worldometers.info/coronavirus/.
3. Government of Hong Kong SAR. Cross-boundary passenger traffic estimation and arrangements for Lunar New Year festive period. 7 Feb 2018. https://www.info.gov.hk/gia/general/201802/07/P2018020700291.htm.
4. The Japan Times. Japan reports first domestic transmission of coronavirus. 28 January 2020. https://www.japantimes.co.jp/news/2020/01/28/national/japan-first-domestic-transmission-coronavirus/.
5. Global News. German man who never visited china catches coronavirus through human-to-human transmission. 28 January 2020. https://globalnews.ca/news/6472303/german-coronavirus-human-to-human-transmission/.