George Bernard Shaw (2015). “George Bernard Shaw: The Collected Plays (Illustrated): 60 plays including Caesar and Cleopatra, Pygmalion, Saint Joan, The Apple Cart, Cymbeline, Androcles And The Lion, The Man Of Destiny, The Inca Of Perusalem and Macbeth Skit”, p.3638, e-artnow
Pitirim Aleksandrovich Sorokin (2002). “The Ways and Power of Love: Types, Factors, and Techniques of Moral Transformation”, p.12, Templeton Foundation Press