found: Acosta, M. de. Papers, 1855-1964(hdg.: Marie Doro; usage: Marie Stewart; Marie Doro)
found: Who was who in the theatre, 1978(Doro, Marie, actress; b. Duncannon PA, 25 May 1882, daughter of E.H. Stuart, m. Elliot Dexter, d. 9 Oct. 1956)
found: IMDB, Dec. 12 2008(Doro, Marie, b. 1882, d. 1956 in New York, birth name Marie K. Steward)
found: Garraty, John A., Mark C. Carnes, and American Council of Learned Societies. American National Biography. New York: Oxford UP, 1999:(Doro, Marie; May 25, 1882-Oct. 9, 1956; actress; wrote and published popular songs)