Early Ordovician graptolites in Mongolia. KALJO, D.; KOREN, T.N.[Eds]. Graptolites and stratigraphy. Akad. Nauk Ehstonskoi SSR (Inst. 1-256., Geol.), Tallin., 1973: 44-55. Chapter pagination: 222-233. 225 [Zoological Record Volume 110]