Williamson, Harold Francis, 1901- Northrwestern Mutual Life; a century of trusteeship, by Harold F. Williamson and Orange A. Smalley. Illustrate by John Favagasso. Evanstons, I11. Northrwestern University Press, 1957. 368 p. ilus. regratos color., mapas color. diagrs. facsíms, tablas. 29 cm. (Northrwestern University, studies in bussiners history, v.4) Bibliografía: p. [319]-321