Natural Boundaries -- See Boundaries Here are entered works on boundaries in general. Works on boundaries of specific regions, countries, etc., are entered under the name of the place with the subdivision Boundaries. Works on the boundaries between two countries, etc., are entered under the name of each country with the subdivision Boundaries--[other country], e.g. United States--Boundaries--Mexico; Mexico--Boundaries--United States. --subdivision Boundaries under names of countries, states, etc.; and subdivision Territorial questions under individual wars, e.g. World War, 1939-1945--Territorial questions