English/Chinese Bilingual Philatelic Glossary on Termbases.eu
Website: https://www.termbases.eu/
Canadian Elizabethan Stamp Glossary by Elizabeth II Study Group (BNAPS)
Website: https://www.adminware.ca/esg/
United States Postal Service (USPS) Abbreviations Glossary by Douglas Boynton Quine
Website: https://www.quine.org/
Glossary of Philatelic Terms on USPS
Website: https://www.usps.com/
Philatelic Terminology on Wikipedia
Website: https://en.wikipedia.org/