1. Bettendorf H (1897) Ueber Musculatur und Sinneszellen der Trematoden. Zool Jahrb Anat 10:307–358
2. Koelle GB (1951) The elimination of enzymatic diffusion artifacts in the histochemical localization of cholinesterases (ChE's) and a survey of their cellular distribution. J Pharmacol Exp Ther 103:152–171
3. Kolmogorova EJa (1959) The structure of the central parts of the nervous system ofOpsthorchis felineus. (in Russian) Zool Zh 38:1627–1633
4. Kotikova EA (1967) Histochemical method for studying the morphology of the nervous system in flatworms. (in Russian) Parazitologiia 1:79–81
5. Kotikova EA (1969) Cholinesterase of trematodes and the structure of their nervous system. (in Russian) Parazitologiia 3:532–537