@article {k56, title = {Immunization against Poliomyelitis with Living Attenuated Virus}, journal = {The American Journal of Tropical Medicine and Hygiene}, volume = {5}, number = {3}, year = {1956}, pages = {440-452}, url = {https://www.ajtmh.org/content/journals/10.4269/ajtmh.1956.5.440}, author = {Koprowski, H.} }