1. Selection for Neuroblastoma Cells that Synthesize Certain Transmitters Creator: Nirenberg, Marshall W.Breakefield, Xandra O. Date: June 1974 Publisher: National Academy of Sciences (U.S.) Genre: Articles
2. Letter from Xandra Breakefield to Marshall W. Nirenberg Creator: Breakefield, Xandra O. Date: 19 February 1962 Genre: Letters (correspondence)
3. Letter from Xandra Breakefield to Marshall W. Nirenberg Creator: Breakefield, Xandra O. Date: 25 March 1962 Genre: Letters (correspondence)