Davydov, VI, Leven, EJ. (2003). Correlation of Upper Carboniferous (Pennsylvanian) and Lower Permian (Cisuralian) marine deposits of the Peri-Tethys
.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY, 196(1-2), 39-57. 10.1016/S0031-0182(03)00312-2
Davydov, VI, Leven, EJ. (2003). Correlation of Upper Carboniferous (Pennsylvanian) and Lower Permian (Cisuralian) marine deposits of the Peri-Tethys
. PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY, 196(1-2), 39-57. 10.1016/S0031-0182(03)00312-2