Willis, B. (1930). Living Africa: A geologist's wanderings through the rift valleys. Whittlesey House, McGraw-Hill.
Dyfyniad Arddull ChicagoWillis, Bailey. Living Africa: A Geologist's Wanderings Through the Rift Valleys. [New York]: Whittlesey House, McGraw-Hill, 1930.
Dyfyniad MLAWillis, Bailey. Living Africa: A Geologist's Wanderings Through the Rift Valleys. Whittlesey House, McGraw-Hill, 1930.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.