"Foursome: Alfred Stieglitz, Georgia O'Keeffe, Paul Strand, Rebecca Salsbury" (Alfred A. Knopf), by Carolyn Burke It's been almost a century since Alfred Stieglitz scandalized polite society with nude photographs of his lover and soon-to-be-wife Georgia O'Keeffe. One of the visitors to his 1921 exhibition was Paul Strand, the brilliant ...