[1] Alsina, C., Trillas, E., On the symmetric difference of fuzzy sets, Fuzzy Sets and Systems, 153 (2005),
181 -194.
[2] Apostol, T. M., Mathematical Analysis, 5th printing, Addison-Wesley Publishing Company, Massachusetts,
1981.
[3] Bhat, B. R., Modern Probability Theory: An Introductory Textbook, Wiley Easten Limited, New Delhi,
1981.
[4] Feller, W., An Introduction to Probability Theory and its Applications, vol. 1, John Wiley and Sons, Inc.,
New York, 1968.
[5] Feller, W., An Introduction to Probability Theory and its Applications, vol. 2, John Wiley and Sons, Inc.,
New York, 1991.
[6] Folland, G. B., Real Analysis: Modern Techniques and Their Applications, 2nd ed., John Wiley and Sons,
Inc., New York, 1999.
[7] Gaspar, M. B., Martin, F., A procedure for computing the symmetric difference of regions defined by
polygonal curves, J. Symbolic Comput., 61 (2014), 53-65.
[8] Givant, S., Halmos, P. R., Introduction to Boolean Algebra, Springer, New York, 2009.
[9] Halmos, P. R., Naive Set Theory, Springer, New York, 1998.
[10] Hosseini, M., The associativity of the symmetric difference, Math. Mag., 79 (2006), 391-392.
[11] Larson, H. J., Introduction to Probability Theory and Statistical Inference, 3rd ed., John Wiley and Sons,
Inc., New York, 1982.
[12] Lin, S. Y. T., Lin, Y., Set Theory with Applications, Mariner Publishing Company, Boston, 1981.
[13] Luciano, D., Gordon, P., Cryptography: from Caesar ciphers to public-key cryptosystems, College Math.
J., 18 (1987), 2-17.
[14] Niven, I., Mathematics of Choice: Or, How to Count Without Counting, Mathematical Association of
America, Washington, DC, 1977.
[15] Sigler, L. E., Exercises in Set Theory, Springer-Verlag, New York, 1976.
[16] Sinkov, A., Elementary Cryptanalysis: A Mathematical Approach, Mathematical Association of America,
Washington, DC, 1966.
[17] Stewart, I., Tall, D., The Foundations in Mathematics, 2nd ed., Oxford University Press, Oxford, 2015.
[18] Williams, M., Difference sets and the symmetric difference, Master‘s thesis, Sam Houston State University,
2022.
[19] Yūsifī, M., A proof for associativity of the symmetric difference, Roshd Amūzish Rīyāzī, 4 (1986), 25-26.
[in Persian]