Robert N. Kirchdoerfer, Christopher A. Cottrell, Nianshuang Wang, Jesper Pallesen, Hadi M. Yassine, Hannah L. Turner, Kizzmekia S. Corbett, Barney S. Graham, Jason S. McLellan, Andrew B. Ward,
Pre-fusion structure of a human coronavirus spike protein Nature. ,vol. 531, pp. 118- 121 ,(2016) ,
10.1038/NATURE17200