Columbia subject headings:
Geology--Study and teaching (Higher)--Canada--Directories.
Geology--Study and teaching (Higher)--Mexico--Directories.
Geology--Study and teaching (Higher)--United States--Directories.
Harvard subject headings:
Princeton subject headings:
Geology--Study and teaching (Higher)--Canada--Directories--Periodicals.
Geology--Study and teaching (Higher)--Mexico--Directories--Periodicals.
Geology--Study and teaching (Higher)--United States--Directories--Periodicals.
Universities and colleges--Canada--Directories--Periodicals.
Universities and colleges--Mexico--Directories--Periodicals.
Universities and colleges--United States--Directories--Periodicals.