James Shirley (1833). “The Dramatic Works and Poems of James Shirley, Now First Collected: The grateful servant. The traitor. Love's cruelty. Love in a maze. The bird in a cage. Hyde Park”, p.174
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.186