Sarasota's Numismatic Guaranty Co. graded coins that sold at

Ben Wengel - Senior Grading Finalizer of World Coins - Numismatic Guaranty Company (NGC)

Sarasota company grades coin that sold for $4 million - Yahoo Sports

NUMISMATIC GUARANTY CORPORATION OF AMERICA, NGC - 23 Reviews - Sarasota, Florida - Local Services - Phone Number - Yelp

Understanding Grading & Certification

Group of NGC-certified Massachusetts Coins Realizes Over $2.9 Million

NGC Certifies First Sacagawea-Presidential Dollar Mule

Numismatic Guaranty Company - Wikipedia

Catalog - Page5, Live Auction - Apr 7th San Francisco Spring Coin Auction-14984 by Gold Standard Auctions

Numismatic Guaranty Corporation Grades 40,000,000 Coins

NGC-certified Edward VIII Gold 5 Sovereign Realizes $2.45 Million, a New Record for a British Coin at Auction