- Defining constant versus variable phenotypic features of women with polycystic ovary syndrome using different ethnic groups and populations. Welt, C.K., Arason, G., Gudmundsson, J.A., Adams, J., Palsd??ttir, H., Gudlaugsd??ttir, G., Ingad??ttir, G., Crowley, W.F. J. Clin. Endocrinol. Metab. (2006)