The historicist school of thought persisted well in to the 20th century, represented in the works of scholars such as David Carrasco, Miguel León Portilla, Nigel Davies and H. B. Nicholson, which all held the Toltecs to have been an actual ethnic group. This school of thought connected the "Toltecs" to the archaeological site of Tula, which was taken to be the Tollan of Aztec myth.[7] This tradition assumes that much of central Mexico was dominated by a "Toltec empire" between the 10th and 12th century CE. The Aztecs referred to several Mexican citystates as Tollan, "Place of Reeds", such as "Tollan Cholollan". Archaeologist Laurette Sejourné, followed by the historian Enrique Florescano, have argued that the "original" Tollan was probably Teotihuacán. Florescano adds that the Mayan sources refer to Chichén Itzá when talking about the mythical place Zuyua (Tollan).