Picasso biographer John Richardson, Cahiers d'Art's Staffan Ahrenberg and Sotheby's Philip Hook preview the extraordinary new edition of Christian Zervos' unequalled and historic 33-volume Picasso Catalogue.This massive undertaking became Zervos’s life work and one of the most influential pieces of scholarship on the 20th century’s most renowned artist. Reserve your set at zervos.sothebys.com.