Kistner, Otfried, et al. “[Development of a Novel Influenza Vaccine Derived from a Continuous Cell Line] [Article in German]: LINZ 2000”. ALTEX - Alternatives to Animal Experimentation, vol. 18, no. 1, Feb. 2001, pp. 50-54, https://altex.org/index.php/altex/article/view/1375.