Columbia subject headings:
Laryngoscopy.
Larynx--Diseases--Treatment.
Medical instruments and apparatus.
Medicine--Formulae, receipts, prescriptions.
Pharynx--Diseases--Treatment.
Throat--Diseases--Treatment.
Trachea--Diseases--Treatment.
Harvard subject headings:
Larynx--Diseases
Pharynx--Diseases
Throat--Diseases
Trachea--Diseases
Princeton subject headings:
Larynx--Diseases.
Pharynx--Diseases.
Throat--Diseases.
Trachea--Diseases.