Columbia subject headings:
Beans--Panama--Statistics--Periodicals.
Corn--Panama--Statistics--Periodicals.
Rice--Panama--Statistics--Periodicals.
Harvard subject headings:
Beans--Panama--Statistics--Periodicals.
Corn--Panama--Statistics--Periodicals.
Rice--Panama--Statistics--Periodicals.
Princeton subject headings:
Beans--Panama--Statistics--Periodicals.
Corn--Panama--Statistics--Periodicals.
Rice--Panama--Statistics--Periodicals.