MalyarenkoA., and OlenkoA. “Many-Dimensional Covariant Random Fields on the Commutative Locally Compact Groups”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 44, no. 11, Nov. 1992, pp. 1505-10, https://umj.imath.kiev.ua/index.php/umj/article/view/8252.