Concussion Guidelines in National and International Professional and Elite Sports. Issue 2 (1st August 2020) - Davis, Gavin A; Makdissi, Michael; Bloomfield, Paul; Clifton, Patrick; Cowie, Charlotte; Echemendia, Ruben; Falvey, Eanna C; Fuller, Gordon Ward; Green, Gary Alan; Harcourt, Peter; Hill, Jerry; Leahy, Kevin; et al.