The map shows the locations of the two leading Italian trading and banking houses of the 14th and 15th centuries. Branches of the Peruzzi bank around 1336 are shown in red, branches of the Medici bank about 100 years later in yellow. Both had their headquarters, indicated by a black frame, in Florence.
P. Benoit (1989) Calcul, algèbre et marchandise In: M. Serres (editor), Éléments d'histoire des sciences. Bordas, Paris, pp. 197-221.