The Middle Cenomanian basal series of Planinica, Western Serbia - Rabrenović, Dragoman; Vasić, Nebojša; Mitrović-Petrović, Jovanka; Radulović, Vladan; Radulović, Barbara; Srećković-Batoćanin, Danica (Geološki anali Balkanskoga poluostrva, 2002)