A symbolic-arithmetic for teaching double-black node removal in red-black trees. Educational Dimension, Kryvyi Rih, Ukraine, v. 7, p. 112–129, 2022. DOI: 10.31812/educdim.7629. Disponível em: https://journal.kdpu.edu.ua/ed/article/view/8258. Acesso em: 5 dec. 2025.