Columbia subject headings:
Harvard subject headings:
Kessel, Johannes 1839-1907
Kessel, Johannes 1839-1907--Correspondence.
Mach, Ernst, 1838-1916--Correspondence.
Otolaryngologists--Germany--Biography.
Physicians--Germany--Biography
Princeton subject headings:
Kessel, Johannes 1839-1907--Correspondence.
Kessel, Johannes 1839-1907.
Mach, Ernst, 1838-1916--Correspondence.
Otolaryngologists--Germany--Biography.
Physicians--Germany--Biography.