American Topical Association - "The American Topical Association is composed of members who specialize in thematic or topical philatelic collecting. Those who share a specific topic band together to form "study units." These units promote their specific topic and encourage research on that topic."

American Topical Association National Topical Stamp Show:
"The American Topical Association is composed of members who specialize in thematic or topical philatelic collecting. Those who share a specific topic band together to form "study units." These units promote their specific topic and encourage research on that topic."

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