Columbia subject headings:
Harvard subject headings:
Biographies
Friedrich IV, Duke of Saxe-Gotha-Altenburg, 1774-1825.
Saxe-Altenburg (Germany)--History.
Saxe-Altenburg (Germany)--Kings and rulers--Biography.
Thuringia (Germany)--History
Thuringia (Germany)--Kings and rulers--Biography.
Princeton subject headings:
Saxe-Altenburg (Germany)--History.
Saxe-Altenburg (Germany)--Kings and rulers--Biography.