Ople, B. F. (1997). Manila Declaration. IN Horizons [column]: A social clause for global tourism. Manila Bulletin.
Chicago-viite (17. p.)Ople, Blas F. "Manila Declaration. IN Horizons [column]: A Social Clause for Global Tourism." Manila Bulletin 1997.
MLA-viite (9. p.)Ople, Blas F. "Manila Declaration. IN Horizons [column]: A Social Clause for Global Tourism." Manila Bulletin, 1997.
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