Guardian (online), viewed July 23, 2014 (Isabel de Madariaga; b. Isabel Margaret de Madariaga, Aug. 27, 1919, Glasgow; d. June 16, 2014; expert on Russian history who wrote acclaimed books on Catherine the Great and Ivan the Terrible)
Russia in the age of Catherine the Great, c1981 t.p. (Isabel de Madariaga) CIP data sheet (b. 1919)