Columbia subject headings:
Harvard subject headings:
Bernoulli, Martha, 1863-1959--Correspondence.
Pharmacists--Switzerland--Correspondence.
Pharmacy--Switzerland--History--Sources.
Tschirch, A. (Alexander), 1856-1939--Correspondence.
Princeton subject headings:
Bernoulli, Martha, 1863-1959--Correspondence.
Pharmacists--Switzerland--Biography.
Tschirch, A. (Alexander), 1856-1939--Correspondence.