Source
- Man and Superman: A Comedy and a Philosophy (1903), Act 2, p.50.
Bynum, W. F.; Porter, Roy, eds. (2006). "Shaw, George Bernard". The Oxford Dictionary of Scientific Quotations. Oxford University Press. Retrieved 2 December 2009.
Bynum, W. F.; Porter, Roy, eds. (2006). "Shaw, George Bernard". The Oxford Dictionary of Scientific Quotations. Oxford University Press. Retrieved 2 December 2009.