GRANT, Cameron Jason; TALVILA, Erik. Elementary Numerical Methods for Double Integrals. Minnesota Journal of Undergraduate Mathematics, [S.l.], v. 4, n. 1, june 2019. ISSN 2378-5810. Available at: <https://mjum.math.umn.edu/index.php/mjum/article/view/67>. Date accessed: 03 dec. 2020.