Columbia subject headings:
Coastal engineering--Germany--Oldenburg--Sources.
Landesbibliothek Oldenburg (Lower Saxony, Germany)--Catalogs.
Tenge, Oskar, 1832-1913--Manuscripts--Catalogs.
Harvard subject headings:
Dikes (Engineering)--Germany--History.
Hydraulic engineers--Germany--Biography.
Landesbibliothek Oldenburg (Lower Saxony, Germany)--Catalogs.
Tenge, Oskar, 1832-1913--Archives--Catalogs.
Princeton subject headings: