Marinkelle, C. J.; Sanchez, N. de .; Grögl, M. .; Guhl, F. . Reconunendations for the Storage Iof Serum Absorbed on Filter Paper in Rural Area, Fot the Diagnosis of Chagas’ Disease by Immunofluorescent Test. Rev. Inst. Med. Trop. São Paulo 1978, 20 (2), 112-114.