Schneider U, Schwenk H, Bornkamm G (1977). "Characterization of EBV-genome negative "null" and "T" cell lines derived from children with acute lymphoblastic leukemia and leukemic transformed non-Hodgkin lymphoma". Int J Cancer19 (5): 621–6. PMID68013. doi:10.1002/ijc.2910190505.
Schneider U, Schwenk H, Bornkamm G (1977). "Characterization of EBV-genome negative "null" and "T" cell lines derived from children with acute lymphoblastic leukemia and leukemic transformed non-Hodgkin lymphoma". Int J Cancer19 (5): 621–6. PMID68013. doi:10.1002/ijc.2910190505.