Armstrong, H.A., Abbott, G.D., Turner, B.R., Makhlouf, I.M., Muhammad, A.B., Pedentchouk, N., Peters, H., "Black shale deposition in an Upper Ordovician-Silurian permanently stratified, peri-glacial basin, southern Jordan.", Palaeogeography, Palaeoclimatology, Palaeoecology, 2009