| aslrra.org | American Short Line and Regional Railroad Association |
| permanentwayinstitution.com | Permanent Way Institution |
| aar.org | AAR - Association of American Railroads |
| swedishtrade.se | SWERIG - Swedish Rail Industry Group |
| dot.gov | U.S. Department of Transportation |
| amtrak.com | Amtrak - Catch The Next Wave In Train Travel |
| bakfjs.org | Bulgarian Association of Consulting Companies in Railway Construction. |
| aera.co.uk | AERA - Association of European Rail Agents |
| uic.asso.fr | UIC - International Union of Railways |
| trackbed.com | Permanent Way Institution |
United States , Colorado , Pueblo