1. Heinz, Virchow's Arch.122, 112 (1890).
2. Moeschlin, Folia Haemat.65, 345 (1941); Schweiz. med. Wschr.26, 789 (1941).
3. Nizet, Acta biol. Belg.1, 402 (1941); Acta med. Scand.117, 199 (1944).
4. Nizet, loc. cit. Acta biol. Belg.1, 402 (1941)
5. Moeschlin, loc. cit. Acta biol. Belg.1, 402 (1941)