William Butler Yeats is the author of The Green Helmet (1910), The Collected Works in Verse and Prose of William Butler Yeats: Ideas of good and evil (1908), The Collected Works of William Butler Yeats: Ideas of good and evil (1908), The Collected Works in Verse and Prose of William Butler Yeats: The secret rose. Rosaalchemica. The table of the law. Adoration of the magi. John Sherman. Dhoya (1908), Discoveries (1907).