Resources found in the Smithsonian National Postal Museum Library are:
- Luff, John N., 1905. A Reference List of the Stamps of Panama, The Scott Stamp and Coin Co., New York. HE6185P2L94 1905.
- Myer, John N., 1940. Studies in the Philately of Colombia. New York. HE6185C7M99 1940.
- Mitchell Jr., Robert L. and Robert A. D’Elia. 2001. A Philatelic Bibliography for Colombia and Panama 1865 - 1999. Colombia/Panama Philatelic Study Group. HE6185C7M58 2001.