Columbia subject headings:
Harvard subject headings:
Engineers--Germany--Biography.
Heating--Biography.
Rietschel, H. (Hermann), 1847-1914.
Ventilation--Biography.
Princeton subject headings:
Air conditioning--History.
Environmental engineers--Germany--Biography.
Heating--History.
Rietschel, H. (Hermann), 1847-1914.
Ventilation--History.