William Cowper (1856). “The task, Table talk, and other poems: With critical observations of various authors on his genius and character, and notes, critical and illustrative”, p.220
William Cowper, Robert Southey (1854). “The Works of William Cowper: Letters, 1788-1799. Papers in the Connoisseur. Letter from an owl to a bird of paradise. Fragment of an intended commentary on Paradise lost. Account of the treatment of his hares”, p.334
William Cowper (1851). “The Works of William Cowper: His Life, Letters, and Poems. Now First Completed by the Introduction of Cowper's Private Correspondence”, p.671
William Cowper, James Thomson (1832). “The Works of Cowper and Thompson: Including Many Letters and Poems Never Before Published in this Country. With a New and Interesting Memoir of the Life of Thomson”, p.118
William Cowper, William Hayley, John William Cunningham (1854). “The Works of William Cowper: His Life, Letters, and Poems ; Now First Completed by the Introduction of Cowper's Private Correspondence”, p.211