311.2 Yul I Yule, George Udny, 1871- An introduction to the theory of statistics. by G. Udny Yule … with 53 figures and diagrams. 6th ed., enl. London, C. Griffin and company, limited, 1917. xv, 415 p. tables (1 fold.) diagrs. (2 fold) 19½ cm. (Lettered on cover: Friffin´s scientific text-books) Contains references.