"The Shakespeare Book of Lists : The Ultimate Guide to the Bard, His Plays, and How They'Ve Been Interpreted (And Misinterpreted) Through the Ages". Book by Michael Lomonico, 2001.
William Shakespeare, Samuel Johnson, George Steevens (1813). “The Plays of William Shakespeare: In Twenty-one Volumes, with the Corrections and Illustrations of Various Commentators, to which are Added Notes”, p.186
"'I had this fateful Romeo and Juliet idea that love involved pain': Harry Potter's Emma Watson grows up". Interview with John Hiscock, www.mirror.co.uk. September 21, 2012.