1. Redefinition of the Pennsylvanian–Permian boundary in Kansas, mid-continental USA;Baars;Int. Geol. Rev.,1992
2. Proposed repositioning of the Pennsylvanian–Permian boundary in Kansas;Baars;Kansas Geol. Surv. Bull.,1994
3. Redefinition of the Upper Pennsylvanian Virgilian Series in Kansas;Baars;Kansas Geol. Surv. Bull.,1994
4. A provisional conodont zonation for Late Pennsylvanian (late Late Carboniferous) strata in Midcontinent region of North America;Barrick;Newsl. Carboniferous Stratigraphy,2000
5. Microfacies y microfósiles de las rocas carbonatadas del Paleozoico de San Salvador Patlanoaya;Brunner,1987