Tahri, Y; Chermette, H; Elkhatib, N; Krupa, J; Simoni, E (1990). "Electronic structures of thorium and protactinium halide clusters of [ThX8]4− type". Journal of the Less Common Metals158: 105. doi:10.1016/0022-5088(90)90436-N.
Morss, Lester R.; Edelstein, Norman M.; Fuger, J. (2010). The chemistry of the actinide and transactinide elements. Volumes 1-6. Dordrecht: Springer. p. 874. ISBN978-94-007-0211-0. கணினி நூலகம்682907473.