Sumathipala, A.; Siribaddana, Sisira; Fernando, D.S.J.; Abeysinghe, M.R.N.; De Silva, N.; Hotopf, M.
(Cambridge university, 2003-02)
The National Twin Registry of Sri Lanka was established in 1997 as a volunteer register. To extend it to a population-based register, we examined the effectiveness of tracing older twins by inspecting birth records and ...