Enders, B. .; Economy, D. .; Hungerer, K. D. .; Zwisler, O. . Evaluation of a Purified Sghistosoma-Skin Test-Antigen for the Diagnosis of Human Bilharzia Infection Report of Field Triais ín Ethiopia, Rhodesia, Sierra Leone and Brasil. Rev. Inst. Med. Trop. São Paulo 1974, 16 (6), 305-316.