Coba jelasin Sumber dari George S. Morison dong

Historic American Engineering Record (Library of Congress)  – Survey number HAER NE-2. 500+ data pages discuss Chief Engineer George S. Morison and his many bridges

Gerber, E., Prout, H. G., and Schneider, C. C. (1905). “Memoir of George Shattuck Morison.” Trans. Am. Soc. Civ. Eng., Volume 54, 513–521.