Oscar Wilde, Russell Jackson, Joseph Bristow, Ian Small (2000). “The Complete Works of Oscar Wilde: The picture of Dorian Gray : the 1890 and 1891 texts”, p.10, Oxford University Press on Demand
Oscar Wilde, Russell Jackson, Ian Small (2000). “The Complete Works of Oscar Wilde: De profundis, "Epistola : in carcere et vinculis"”, p.119, Oxford University Press on Demand
The Picture of Dorian Gray ch. 4 (1891). In Wilde's play LadyWindermere's Fan, act 3 (1892), Lord Darlington replies to the question "What is a cynic?": "A man who knows the price of everything and the value of nothing."