- Visit Chip Greiner’s Railroad Police History Group on Facebook

- Visit Chip Greiner's eBay store

- View Chip Greiner's Railway Age article on railroad police

- Visit The Garbely Publishing Company, publisher of Chip Greiner's railroad police badge books and designer of this website

- Visit The Railroad Police Website by Retired UP Police Lieutenant Paul Miller

- Visit "Mr. Find It" Collectibles, a source for old police badges