Note VII-3 — Chapter VII · ANTIQUITIES OF OAJACA AND GUERRERO.
Reading edition
Dupaix, 3d exped., pp. 6-7, pl. iii.-v., fig. 6-9; Kingsborough, vol. vi., p. 469, vol. iv., pl. iii.-v., fig. 6-9; Larenaudière, Mex. Guat., pl. viii., from Dupaix, showing second pyramid; Mayer's Observations, pp. 25-6, with cut of the first altar representing its successive platforms as forming a spiral ascent.