1. Letter from Barbara McClintock to Charles R. Burnham Publication: Produced: 4 April 1930 Subject(s): ChromosomesZea maysCrossing Over, GeneticCytogenetics Archival Collection: The Barbara McClintock Papers (Profiles in Science)
2. Letter from Barbara McClintock to Charles R. Burnham Publication: Produced: 23 January 1930 Subject(s): Zea maysChromosomesCrossing Over, GeneticJob Satisfaction Archival Collection: The Barbara McClintock Papers (Profiles in Science)