1. Chia KS, Lee HP, Seow A et al (1992) Trends in cancer incidence in Singapore, 1968–1992. Singapore Cancer Registry Report No. 4:114
2. Hay ID, Bergstralh EJ, Goellner JR et al. (1993) Predicting outcome in papillary thyroid carcinoma: development of a reliable prognostic scoring system in a cohort of 1779 patients surgically treated at one institution during 1940–1989. Surgery 114:1050–1058
3. Cady B, Rossri R (1988) An expanded view of risk group definition in differentiated thyroid carcinoma. Surgery 104:947–953
4. Byar DP, Green SB, Dor P et al. (1979) A prognostic index for thyroid carcinoma: a study of the EORTC Thyroid Cancer Cooperative Group. Eur J Cancer 15:1033–1041
5. Shaha A, Loree TR, Shah JP (1994) Intermediate risk group for differentiated carcinoma of the thyroid. Surgery 116:1036–1042