But twin type is actually a classification of zygosity and defined by how twins form, not by what they look like. (verywellfamily.com)
Average daily macronutrient and food group intakes at age 21 mo and intraclass correlation coefficients for consumers by zygosity: Gemini twin cohort1 (academic.oup.com)
I gave up my crazy zygosity obsession until my daughters turned two. (twiniversity.com)