1. Adler, Alfred. The Practice and Theory of Individual Psychology. Trans. P. Radin. London: Kegan Paul Trubner and Co., 1940.
2. Bariun, Fawzia. “Malik Bennabi and the Intellectual problems of Muslim Ummah.” The American Journal of Islamic and Social Sciences 9/3 (1992), pp. 325-337.
3. Darwin, Charles. The Origin of Species (London: John Murray, 1859), at: https://www.vliz.be/docs/Zeecijfers/Origin_of_Species.pdf.
4. Marx, Karl and Engels, Friedrich. the communist Manifesto, (ed.) Samuel H. Berr, New York: Appleton-Century-Crofts, 1955, at: https://www.bard.edu/library/arendt/pdfs/Marx-CommunistManifesto.pdf
5. Freud, Sigmund. The Civilization and its Discontents (London, England: Penguin Classics) pp. 82-85, at: https://www.sas.upenn.edu/~cavitch/pdf-library/Freud_SE_Civ_and_Dis_complete.pdf