Coyle, M., Garside, P., Kelsall, M. & Peck, J. (eds.) (1993). Encyclopedia of Literature and Criticism. London: Routledge.
Croxall,T.H.(1955). Meditations from Kierkegaard. London: James Nisbet and Company, LTD.
Cooper, D. E. (2003). “Soren Kierkegaard”. In R. C. Solomon, & D. Sherman (Eds.), The Blackwell Guide to continental Philosophy. UK: Blackwell Publishing Ltd.
Dobrez, L.A. (2013). The Existential and Its Exits, Literary and Philosophical Perspectives On the Works of Becket, Ionesco, Genet and Pinter. London & New York: Bloomsbury Publishing.
Dreyfus, H. L. (2006). "The Roots of Existentialism". In H. L. Dreyfus, & M. A. Wrathall (Eds.), A Companion to Philosophy and Existentialism. Oxford: Blackwell Publishing.
Esslin, M. (2001) The Theatre of the Absurd. 3rd ed. Vintage Books, a division of Random House, Inc., New York.
Fischer-Lichte, E. (2002). History of European drama and theatre. (J. Riley Trans.) London and New York: Routledge, Psychology Press. (original work published 1990).
Flynn, T. R. (2006). Existentialism: A Very Short Introduction. N.Y: Oxford University Press.
Gray, J. G. (1951). The Idea of Death in Existentialism. Journal of Philosophy, Vol. 48, No.5, (Mar. 1, 1951), P.113-127.
Guignon, C. & Pereboom, D. (eds.) (1995). Existentialism: Basic Writings. Indianapolis, Ind.: Hackett.
Ionesco, E. (1960). The Killer and Other Plays. (D. Watson. trans.) New York: Grove Press.
--------------- (1962). Works of Love, Some Christian Reflections in the Form of Discourses, (Howard and Edna Hong, trans.), Harper Torchbooks, The Cloister Library. New York: Harper & Row. (original work published 1847).
---------------- (1964). Notes and Counter Notes. New York: Grove Press.
---------------- (1968). Fragments of a Journal. (J. Stewart, trans.). London: Faber and Faber Ltd. (Original work published 1967).
Kamyabi Mask, A. (1382). Ionesco and his Theater. (Original work in French), Persian Translation, Tehran: Namayesh Publications
Kierkegaard, S. (1941). Concluding Unscientific Postscript. (D. F. Swenson & W. Lowrie. trans), Princeton: Princeton University Press. (original work published 1846).
-------------------- (1951). Journals (A. Dru, ed. and trans.). London: Oxford University Press (original work published 1923).
-------------------- (1978). Journals and Papers, 7 vols, (Howard V. Hong and Edna H. Hong, trans.), Bloomington and Indianapolis: Indiana University Press.
-------------------- (1980). The Concept of Anxiety. (Reidar Somte, editor & trans.). Princeton University Press, Princeton, New Jersey. (Original work published 1844).
-------------------- (1985). Philosophical Fragments (H. and E. Hong, eds.) pubished in one voluem with Johannes Climacus. Princeton: Princeton University Press, NJ. (original work published 1844).
--------------- (1990). Eighteen Upbuilding Discourses, (Hong, H. & Hong, E., eds. and trans.) Princeton: Princeton University Press.
------------------ (2007). Philosophical Fragments, (Translated by David F. Swenson 1936). Emerald Knight Publishing, Vancouver, British Columbia, Canada. (original work published 1844).
------------------ (2009). Concluding Unscientific Postscript. (A. Hannay, Ed., & A. Hannay, Trans.) united staes: Cambridge University Press. (original work published 1846).
Marino, G. D.(1998). ‘Anxiety in the Concept of Anxiety’. In Hannay, A. & Marino , G. D. (Eds.), The Cambridge Companion to Kierkegaard. Cambridge: Cambridge University Press.
Moore, C. E., (Ed.) (2002). Provocations Spiritual Writings of Kierkegaard. Farmington: The Bruderhof Foundation, Inc.
O'Hara, S. (2004). Kierkegaard within your grasp. Hoboken, NJ: Wiley Publishing, Inc.
O’Meara, W. (2013) "Kierkegaard and Moral Guilt: Can the Ethical Forgive Significant Ethical Failure?" Athens: ATINER'S Conference Paper Series, No: PHI2013-0679.
Parsell, D. B. (2005). ‘Eugene Ionesco’. In C. Rollyson (Eds.) Notable Playwrights (Vol. 2), (pp. 501-15), Baruch College, City University of New York: Salem Press, Inc.
Rudd, A. J. (1998). ‘Kierkegaard and the skeptics’, British Journal for the History of Philosophy, 6:1, 71-88.
Runde, J. Ionesco Beyond Absurdism. Consciousness, Literature and the Arts. Archive - Vol. 8, No.1, (April. 2007). In http://www.dmd27.org/runde.html
Scruton, R., (1998). A short history of modern philosophy: From Descartes to Wittgenstein. London: Routledge.
Tsakiri, V. T. (2006) Kierkegaard Anxiety, Repetition, and Contemporaneity. N. Y: Antony Rowe Ltd, Chippenham and Eastbourne.
Wellwarth G. E. (1962) Eugene Ionesco: The absurd as warning, The Southern Speech Journal, 28:1, 6-16, DOI: 10.1080/10417946209371665.