"Records of Tennyson, Ruskin and Browning," by Annie Ritchie, pp. 291, 292.
"A Bibliography of the Writings of Robert Browning," by T.J. Wise, pp. 157, 158.
Aristophanes' Apology is connected with these poems by its character as a casuistical self-defence of the chief speaker.
North's "Plutarch," 1579, p. 599.
"Les Deux Masques," ii. 281.