1. Manual für die Planung und Durchführung von Therapiestudien;Biefang,1979
2. The ethics of giving placebos;Bok;Scientific American,1974
3. Consent to randomised treatment;Brewin;Lancet,1982
4. Controlled clinical trials and medical ethics;Burkhardt;Lancet,1978
5. Systematic effect of random error in the yoked control design;Church;Psychological Bulletin,1964