R. Kapral and A. Sergi, “Quantum-Classical Wigner-Liouville Equation”, Ukr. Mat. Zhurn., vol. 57, no. 6, pp. 749–756, Jun. 2005, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3641