Thanks to all who responded. The correct citation is:
Donges, J. 1970. Transplantation of rediae - a device for solving
special problems in trematodology. [Abstract]. J. Parasit. 56(4,
Sect.2)(Int. Congr. Parasit. (2nd), Washington DC, Sept. 6-12, 1970,
Proceedings, Part I), pp.82-83.
Thanks again for the help,
Derek Zelmer