The famous "blue catalog" - a study of the 10th anniversary auction of the Marciniak Auction House (then still GNDM).
The auction, the highlight of which was an outstanding collection of medieval coins (items 1-417). The best that was ever offered at public sale. The ornament of which went by right of first refusal to the Royal Castle in Warsaw for 161,000 zlotys.
Today it is not only a souvenir of the auction, but also an important factual study of the Polish Middle Ages. Beautiful photos of often singular values (bracelets of Mieszko III, series of virtues...), extensive descriptions made in consultation with scholars specializing in this section.
You can hear more about the collection in the interview with Dr. Witold Garbaczewski in the video below.