A. N. . Kochubei, “Varieties with invariant half-Rieman structure of almost product ”, Ukr. Mat. Zhurn., vol. 44, no. 7, pp. 926–931, Aug. 1992, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/8125