Akkerman, Nadine N. W. “A Triptych of Dorothy Percy Sidney (1598-1659), Countess of Leicester, Lucy Percy Hay (1599-1660), Countess of Carlisle, and Dorothy Sidney Spencer (1617-1684), Countess of Sunderland”. The Ashgate Research Companion to the Sidneys, 1500-1700 Volume 1: Lives, edited by Margaret P. Hannay et al., Ashgate, 2015.