Tschuprow, A. A. Principles of the mathematical theory of correlation / A. A. Tschuprow ; translated by M. Kantorowitsch. - London : William Hodge and Company, 1939. - x, 194 p. ; 22 cm. Includes bibliographical refrences and index. Subjects--Topical Terms: Correlation (Statistics). LC Class. No.: QA276 / .T73 1939