Naudé amassed 40,000 books for Mazarin within two years

Evidence

After two years of frantic travel, through France, Switzerland, Germany, England and the Netherlands, Naudé had furnished the cardinal with a library of breathtaking size – estimated at 40,000 printed books and 850 volumes of manuscripts. — Andrew Pettegree, Arthur der Weduwen, The Library- A Fragile History, 460

Categorization

• corroborated: 2 independent passages support this claim — Andrew Pettegree, Arthur der Weduwen, The Library- A Fragile History, 460