Shirley, R, Duncan, K, Campos Varillas, M C, Hurley, P D, MaLek, K, Roehlly, Y, Smith, M W L, Aussel, H, Bakx, T, Buat, V, Burgarella, D, Duivenvoorden, S, McCheyne, I, Scudder, J, Oliver, S and others, (2021) HELP: the Herschel Extragalactic Legacy Project. Monthly Notices of the Royal Astronomical Society. ISSN 0035-8711