Lewis six-wheeled truck of the 120-ton coal cars on the Virginian Railway
Unknown author<span style="display: none;">Unknown author</span>
<a rel="nofollow" class="external free" href="https://archive.org/stream/railwaylocomotiv34newy#page/180">https://archive.org/stream/railwaylocomotiv34newy#page/180</a> Railway and Locomotive Engineering, June 1921, Page 180