1. Sex and Death in Protozoa;Bell,1988
2. The articles most cited in 1961–1982. 2. Another 100 citation classics highlight the technology of science;Garfield;Current Contents,1984
3. The limited in vitro lifetime of human diploid cell strains;Hayflick;Exp. Cell Res.,1965
4. Human virus vaccines: Why monkey cells?;Hayflick;Science,1972
5. Citation classics: The serial cultivation of human diploid cell strains;Hayflick;Current Contents,1978