"Historical Armenia's boundaries have varied considerably, but old Armenia extended over what is now the northeastern part of Turkey and the Republic of Armenia." (Encyclopedia Britannica)Descriptive usage tells us that Armenia (Republic) is used for the period after 1991, and for the revolutionary government from 1918-1920, while Armenia refers only to the pre-1918 kingdom.
But Subject usage tells us that the heading Armenia is used for the time period until 1920.
Thus, for the revolutionary government of 1918-1920, there is the confusing situation that the name heading is Armenia (Republic), but subject usage is Armenia.
Descriptive Usage: Name heading for the government for both 1918-1920 and after 1991.
Subject Usage: This heading is used for works on Armenia since 1920. Works on the revolutionary events in the historical region of Armenia, including the Armenian Republic, 1918-1920, are entered under the subject heading Armenia--History--Revolution, 1917-1920.
NAFL9257129
Subject Usage: This heading is used for works on Armenia since 1920. Works on the revolutionary events in the historical region of Armenia, including the Armenian Republic, 1918-1920, are entered under the subject heading Armenia--History--Revolution, 1917-1920.
NAFL9257129
Armenia
Descriptive Usage: Use only for the pre-1918 kingdom of Armenia.
NAFL79111504
NAFL79111504
Armenia
Here are entered works on the historic kingdom and region of
Armenia as a whole to 1920. Works on the parts of Armenia incorporated into
other countries after 1920 are entered under the name of the individual region
or republic.
SAFL857261
SAFL857261