J. S. LEE,Y. T. CHAO HISTORICAL
During his epoch-making exploration in China, von Richthofen~1 divided the Palaeozoic coal-bearing series in Shansi into 3 subdivisions:
J. S. LEE, Y. T. CHAO HISTORICAL.1926. GLASSIFIOATION AND CORRELATION OF PALAEOZOIC COAL-BEARING FORMATIONS IN NORTH OHINA[J]. Acta Geologica Sinica(),5(2):