Columbia subject headings:
Medicine--Specialties and specialists--Certification--United States--Periodicals.
Medicine--Study and teaching (Graduate)--United States--Directories.
Residents (Medicine)--United States--Periodicals.
Harvard subject headings:
Medicine--Specialties and specialists--Certification--United States--Periodicals.
Medicine--Study and teaching (Graduate)--United States--Directories.
Residents (Medicine)--United States--Periodicals.
Princeton subject headings: