Columbia subject headings:
AIDS (Disease)--Etiology.
Cancer--Etiology.
Chronic diseases--Etiology.
L-form bacteria.
Harvard subject headings:
AIDS (Disease)--Etiology
Carcinogenesis.
Chronic diseases--Etiology.
L-form bacteria--Pathogenicity.
Princeton subject headings:
AIDS (Disease)--Etiology.
Cancer--Etiology.
Chronic diseases--Etiology.
L-form bacteria.