Columbia subject headings:
Cycles.
Naval history, Modern.
Navies.
Sea-power--History.
Sea-power--Political aspects.
Warships.
World politics.
Harvard subject headings:
Cycles.
Naval history, Modern.
Navies.
Sea-power--History.
Sea-power--Political aspects.
Warships.
World politics.
Princeton subject headings:
Cycles.
Naval history, Modern.
Navies.
Sea-power--History.
Sea-power--Political aspects.
Warships.
World politics.