Winston Churchill's addree as Home Secretary to Prime Minister Asquith on compulsory sterilization of 'the feeble-minded and insane', as quoted in "'Race', Sport and British Society" edited by Ben Carrington and Ian Mcdonald, 2001.
Karl Marx, Friedrich Engels, Vladimir Ilʹich Lenin (1986). “India, National Liberation and Class Struggles: A Collection of Classical Marxist Writings”