Dispersal of invading trematodes Nicolla skrjabini (Iwanitzky, 1928) and Plagioporus skrjabini Kowal, 1951 (Trematoda: Opecoelidae) in the Volga. - Zhokhov, A. E., Molodozhnikova, N. M., Pugacheva, M. N. (Russian Journal of Ecology, 2006)