Borrello, Ángel V., and P. G. Gareca. “On the Presence of <Nemagraptus gracilis> (Hall) in the Ordovician from the North of San Juan”. Revista De La Asociación Geológica Argentina, vol. 6, no. 3, July 1951, pp. 187-93, https://revista.geologica.org.ar/raga/article/view/962.