26. Hillside agriculture Collection: Billie Jean Isbell Andean Collection Set: Vertical ecology of the Andes: Valley Date: 1996 Format: Image
27. Hillside agriculture Collection: Billie Jean Isbell Andean Collection Set: Vertical ecology of the Andes: Valley Date: 1996 Format: Image
28. Hillside agriculture Collection: Billie Jean Isbell Andean Collection Set: Vertical ecology of the Andes: Valley Date: 1996 Format: Image