

- One of the knotted string objects called "khipu," used for record keeping in the Inka empire.Gary Urton

- Khipu pendants showing three common types of multi-colored cords.Museum für Völkerkunde, Berlin, Germany. Photo (c) Gary Urton. VA#42554

- Inca khipu showing bands of knots, indicating different numerical values.American Museum of Natural History, 41.2-6994. Photo (c) Gary Urton