1. Same same but different: when identical twins are non-identical.
2. Semi-identical twins 'identified for only the second time'.
3. 'Extraordinarily Rare' Semi-Identical Twins Were Born in Australia.
4. Scientists stunned by discovery of 'semi-identical' twins.
5. Michael T. Gabbett et al. Molecular Support for Heterogonesis Resulting in Sesquizygotic Twinning. N Engl J Med 2019; 380:842-849. DOI: 10.1056/NEJMoa1701313