36. Hillside agriculture Collection: Billie Jean Isbell Andean Collection Set: Vertical ecology of the Andes: Valley Date: 1996 Format: Image
37. Hillside agriculture Collection: Billie Jean Isbell Andean Collection Set: Vertical ecology of the Andes: Valley Date: 1996 Format: Image
38. Hillside agriculture Collection: Billie Jean Isbell Andean Collection Set: Vertical ecology of the Andes: Valley Date: 1996 Format: Image