	Authors	Year	Title
	Bai, Jin & Ning	1982	The Devonian biostratigraphy of Guangxi and adjacent area. Peking University Press, 203 p., 37 pls. [Chines.]
	Becker & House	1994	International Devonian goniatite zonation, Emsian to Givetian, with new records from Morocco. Courier Forschungsinstitut Senckenberg 169: 79-135, 10 text-figs., 7 pls., Frankfurt am Main.