- National stamp collecting organization's website provides information about membership, expertizing services, sales circuits, and local clubs.stamps.org
- www.collectors-mall.com/philib/RMPL.htm
- The Postal Museum in rhus, Denmark ...norbyhus.dk/musaarh.html
- The Spellman Museum of Stamps and Postal History is an independent, non-for-profit, educational organization dedicated to learning about the world's cultures through stamps and postal history.www.spellman.org/index.php3?GCS_Session=893c14064d913dd00a3fec17a3f0932e