1. Ahlstrom, C.G., Andrewes, C.N.: Fibroma virus infection in tarred rabbits. J. Path. Bact. 47, 65–86 (1938).
2. Albert, R.E., Newman, W., Altschuler, B.: The dose-response relationship of beta-ray-induced skin tumours in the rat. Radiol. Rev. 15, 410–430 (1961).
3. Andervont, H.B., Dunn, T.B.: Responses of strain DBA/2 mice, without the mammary tumor agent, to oral administration of methylcholanthrene. J. nat. Cancer Inst. 14, 329–339 (1953).
4. Baba, T., Aoki, K., Ishii, M.: Relation between the so-called two-phase theory and summation theory in carcinogenesis. Gann 58, 161–166 (1967).
5. Backmann, W.E., Kennaway, E.L., Kennaway, N.M.: Rapid production of tumours by two new hydrocarbons. Yale J. Biol. Med. 11, 97–102 (1938).