Philippines (Republic). Office of the President & Presidential Economic Staff. (1969). Provincial profile of Zamboanga del Sur. s.n.
Chicago-viite (17. p.)Philippines (Republic). Office of the President ja Presidential Economic Staff. Provincial Profile of Zamboanga Del Sur. [Manila: s.n, 1969.
MLA-viite (9. p.)Philippines (Republic). Office of the President ja Presidential Economic Staff. Provincial Profile of Zamboanga Del Sur. s.n, 1969.
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