Ellsworth, Kenneth G., ed. The Car and Locomotive Cyclopedia of American Practices. 4th ed. Omaha, Neb.: Simmons-Boardman Publishing Co., 1980.

Ellsworth, Kenneth G., ed. The Car and Locomotive Cyclopedia of American Practices. 4th ed. Omaha, Neb.: Simmons-Boardman Publishing Co., 1980.