M. Manev, Hristo. “ALMOST CONTACT B-METRIC STRUCTURES AND THE BIANCHI CLASSIFICATION OF THE THREE-DIMENSIONAL LIE ALGEBRAS”. Ann. Sofia Univ. Fac. Math. and Inf. 102 (December 12, 2015): 133–144. Accessed November 23, 2024. https://ftl5.uni-sofia.bg/index.php/fmi/article/view/67.