Columbia subject headings:
Architecture--Germany--Potsdam.
Persius, Ludwig, 1803-1845.
Harvard subject headings:
Architects--Germany--Biography
Architecture, Modern--19th century--Germany--Prussia.
Architecture--Germany--Prussia--History.
Architecture--Germany--Prussia.
Frederick William IV, King of Prussia, 1795-1861--Art patronage.
Persius, Ludwig, 1803-1845--Diaries.
Princeton subject headings: