Almabsout, Sana N., and Fathia M. Alogab. “The Theoretical Basis of Double Integration”. The Annual Scientific Conference for Undergraduate and Postgraduate Students, Alasmarya Islamic University, vol. 3, Feb. 2026, pp. 5. 74-88, https://conf.asmarya.edu.ly/index.php/scupgs/article/view/990.