Analysis of information sources in references of the Wikipedia article "Protestantism in Russia" in English language version.
The English Quakers, who had made contact with the Doukhobors earlier, as well as the Philadelphia Society of Friends, also determined to help with their emigration from Russia to some other country—the only action which seemed possible.
in the middle of the fourteenth century the Strigolniki heresy broke out in Russia, chiefly in the cities in the north of the country, which gave this movement a proto-Reformation character