Columbia subject headings:
Industries--Tonga--Periodicals.
Tonga--Commerce--Periodicals.
Tonga--Economic conditions--Periodicals.
Tonga. Ministry of Labour, Commerce & Industries--Periodicals.
Harvard subject headings:
Industries--Tonga--Periodicals.
Tonga--Commerce--Periodicals.
Tonga--Economic conditions--Periodicals.
Tonga. Ministry of Labour, Commerce & Industries--Periodicals.
Princeton subject headings: