Keutgen N. Belemnites from the Lower Maastrichtian of Limburg, Aachen and Liege. Palaeoecological studies of Late Carboniferous plant macrofossils from borehole Kemperkoul-1(Sittard, The Netherlands) ; Amerom H. W.J. Van, H. J.M. Pagnier, , 1990. - 72 p. - Текст : непосредственный.