Treaty of Peace between Russia and Estonia
“ Article IV During one year from the day of ratification of the present Treaty, persons of non-Estonian origin living in Estonia, and over eighteen years of age, have the right to opt for Russian nationality; women, and children, less than eighteen years of age, take the nationality of the husband or the father, unless there exists between man and wife any contrary agreement. The people who have opted for Russian nationality must, within a year from the date of their choice, leave Estonian territory ”
