Columbia subject headings:
Geologists--United States--Biography.
Pettijohn, F. J. (Francis John), 1904-1999.
Harvard subject headings:
Geologists--United States--Biography
Pettijohn, F. J. (Francis John), 1904-1999.
Princeton subject headings:
Geologists--United States--Biography.
Pettijohn, F. J. (Francis John), 1904-1999.