Phukon, Ambeswar, and Nabani Narzary. “Hyponormality of Toeplitz Operators on Symmetric-Type Circulant Trigonometric Polynomial Symbols: An Extremal Case”. Communications in Mathematics and Applications 15, no. 3 (November 30, 2024): 959–968. Accessed June 11, 2025. http://rgnpublications.com/journals/index.php/cma/article/view/2891.