1. Causes of high twinning frequencies in Nigeria;Nylander;Prog Clin Biol Res,1978
2. Nylander PPS (1976): Biosocial and clinical studies in twinning in an African and a Caucasian population, M.D. Thesis, University of Aberdeen.
3. Ethnic differneces in twinning rates in Nigeria
4. Pharmaceutical products from plant steroids;Hardman;Trop Sci,1969