Columbia subject headings:
Harvard subject headings:
Knorr, Ludwig, 1859-1921.
Pharmaceutical chemistry--Germany--History--19th century.
Pharmaceutical industry--Germany--History--19th century.
Synthetic drugs--Germany--History--19th century.
Princeton subject headings:
Knorr, Ludwig, 1859-1921.
Pharmaceutical chemistry--Germany--History--19th century.
Pharmaceutical industry--Germany--History--19th century.
Synthetic drugs--Germany--History--19th century.