For a long analysis of the theme, see Rosenthal, Lisa, "Hercules' Distaff", especially p. 128 ff, in Gender, Politics, and Allegory in the Art of Rubens, 2005, Cambridge University Press, ISBN0521842441, 9780521842440, Google Books
Zika, Charles, "Images of Witchcraft in Early Modern Europe", in Levack, Brian P. (ed), The Oxford Handbook of Witchcraft in Early Modern Europe and Colonial America, 2013, Oxford University Press, ISBN0199578168, 9780199578160, Google Books; Russell, pp. 14, 147–148, Nos 103–105; Harbison, Craig. The Art of the Northern Renaissance, pp. 120–121, 1995, Weidenfeld & Nicolson, ISBN0297835122; Bartrum, 69–70; there is a further account of the development of scholarship by Zika in pp. 48–65 here
example, British Museum. This collection, in the British Museum is the pattern book of a workshop probably making inserts for small boxes of sweet delicacies such as were given to the guests at weddings.
Loomis, Roger Sherman, "The Allegorical Siege in the Art of the Middle Ages", American Journal of Archaeology, Vol. 23, No. 3 (Jul.–Sep., 1919), pp. 255–269,JSTOR (free)
