Analysis of information sources in references of the Wikipedia article "Список государств и зависимых территорий Европы" in Russian language version.
From the mid-1800s on the most common, although by no means universal, solution to this problem was to separate Asia from Europe by a complex line running southward through the Urals, jumping in their southern extent to the Ural River, extending through some two-thirds the length of the Caspian Sea, and turning in a sharp angle to run northwestward along the crest of the Caucasus Mountains.
From the mid-1800s on the most common, although by no means universal, solution to this problem was to separate Asia from Europe by a complex line running southward through the Urals, jumping in their southern extent to the Ural River, extending through some two-thirds the length of the Caspian Sea, and turning in a sharp angle to run northwestward along the crest of the Caucasus Mountains.
