Columbia subject headings:
Cholera--Epidemiology.
Communicable diseases--Epidemiology.
Syphilis--Epidemiology.
Tuberculosis--Epidemiology.
Harvard subject headings:
Cholera--Epidemiology.
Communicable diseases--Epidemiology
Syphilis--Epidemiology.
Tuberculosis--Epidemiology.
Princeton subject headings:
Cholera--Transmission.
Communicable diseases.
Syphilis--Transmission.