Philippines. Bureau of Coast and Geodetic Survey. (1983). Ilagan. Philippine Coast and Geodetic Survey.
Chicago-referens (17:e uppl.)Philippines. Bureau of Coast and Geodetic Survey. Ilagan. Manila: Philippine Coast and Geodetic Survey, 1983.
MLA-referens (9:e uppl.)Philippines. Bureau of Coast and Geodetic Survey. Ilagan. Philippine Coast and Geodetic Survey, 1983.
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