English: His most important book was is National Income and Its Composition, 1919--1938, published in 1941, which measured things such as Gross National Product.
Telugu: అతని యొక్క ప్రముఖ గ్రంథం National Income and Its Composition, 1919-1938. ఇది 1941 లో ప్రచురించబడింది.