Columbia subject headings:
Harvard subject headings:
Chlorofluorocarbons--United States.
Metered-dose inhalers--Environmental aspects--United States.
Metered-dose inhalers--Law and legislation--United States.
Ozone layer depletion--United States.
Princeton subject headings:
Chlorofluorocarbons--Government policy--United States.
Drug delivery devices--Government policy--United States.
Lungs--Diseases, Obstructive--Dosimetric treatment.
Metered-dose inhalers--Government policy--United States.