↑Engels, Friedrich (1970) [1892]. "Introduction". Socialism: Utopian and Scientific. Marx/Engels Selected Works. 3. Progress Publishers. http://www.marxists.org/archive/marx/works/1880/soc-utop/index.htm. "From this French text, a Polish and a Spanish edition were prepared. In 1883, our German friends brought out the pamphlet in the original language. Italian, Russian, Danish, Dutch, and Roumanian translations, based upon the German text, have since been published. Thus, the present English edition, this little book circulates in 10 languages. I am not aware that any other Socialist work, not even our Communist Manifesto of 1848, or Marx's Capital, has been so often translated. In Germany, it has had four editions of about 20,000 copies in all."
উৎস
Carlton, Grace (1965), Friedrich Engels: The Shadow Prophet, London: Pall Mall Press
Carver, Terrell (1989), Friedrich Engels: His Life and Thought, London: Macmillan
Green, John (2008), Engels: A Revolutionary Life, London: Artery Publications, ISBN 0-9558228-0-7
Henderson, W. O. (1976), The life of Friedrich Engels, London : Cass, 1976. ISBN 0-7146-4002-6
Hunt, Tristram (2009), The Frock-Coated Communist: The Revolutionary Life of Friedrich Engels, London: Allen Lane. ISBN 978-0-7139-9852-8
Mayer, Gustav (1936), Friedrich Engels: A Biography, (1934; trans. 1936)