1. Adams, J. E., Martin W. E.: Life cycle of Himasthla rhigedana Dietz, 1909 (Trematoda: Echinostomatidae). Trans. Amer. micr. Soc. 82, 1–6 (1963).
2. Agarwal, S. M., Tiwari, I. P.: On the egg and miracidium of Paryphostomum bubulcusi Agarwal, 1958 (Trematoda: Echinostomatidae). Indian J. Helminth. 20, 111–117 (1968).
3. Ahluwalia, S. S.: Studies on some helminths of the domestic pig (Sus scrofa domestica) in Western Uttar Pradesh. J. Helminth. 36, 347–364 (1962).
4. Baier, H.: Immunbiologische Untersuchungen an weißen Ratten bei ein- und mehrmaliger Infestation mit dem Darmegel Isthmiophora (Echinostomatidae). Med. Diss. Tübingen, 55 S., 1967.
5. Beaver, P. C.: Experimental studies on Echinostoma revolutum (Froelich), a fluke from birds and mammals. Illinois biol. Monogr. 15, 1–96 (1937).