APA

(1999). Secret hydrographic surveys in the Spratly Island. London: ASEAN Academic Press.

Chicago

1999. Secret hydrographic surveys in the Spratly Island. London: ASEAN Academic Press.

Harvard

(1999). Secret hydrographic surveys in the Spratly Island. London: ASEAN Academic Press.

MLA

Secret hydrographic surveys in the Spratly Island. London: ASEAN Academic Press. 1999.