Lachica, E. (1984). Ayala, the Philippines' oldest business house. Filipinas Foundation.
Chicago-viite (17. p.)Lachica, Eduardo. Ayala, the Philippines' Oldest Business House. Makati, Philippines: Filipinas Foundation, 1984.
MLA-viite (9. p.)Lachica, Eduardo. Ayala, the Philippines' Oldest Business House. Filipinas Foundation, 1984.
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