Lavery, David, Masson, Cynthea, Cochran, Tanya, Wilcox, Rhonda V. Reading Joss Whedon. pp. 116, 137 (Syracuse University Press; 2014) (Project Muse30944)
Stein, Atara. The Byronic Hero in Film, Fiction, and Television. p. 216 (Southern Illinois University Press; 2004) (Project Muse41925)
Amy Kind (2010) "The Vampire with a Soul: Angel and the Quest for Identity". p. 87. In The Philosophy of Horror (Fahy, Thomas; ed.) (University Press of Kentucky) (Project Muse665)
Joyce Millman (2014). "Angel". pp. 30–31. In The Essential Cult TV Reader (Lavery, David; ed.) (University Press of Kentucky) (Project Muse37209)
Abbott, Stacey. Angel. pp. 56–57 (Wayne State University Press; 2009) (Project Muse7897)
