1. H. Beeuwkes enF. A. Bannink, Acta Leidensia12/13, 122, 1938.
2. P. Buchner, Arch. f. Protistenkunde46, 225, 1923.
3. P. Buchner, Tier und Pflanze in Symbiose. Berlin, 1930.
4. E. V. Cowdry, J. exp. Med.41, 817, 1925.
5. J. T. Duncan, Parasitology28, 238, 1926.