Manuel, E. A. (1991). Subterranean structures in Intramuros, the walled city of Manila: A germinal paper. Manila Studies Program, College of Arts and Sciences, University of the Philippines.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रManuel, Esperidion Arsenio. Subterranean Structures in Intramuros, the Walled City of Manila: A Germinal Paper. Manila: Manila Studies Program, College of Arts and Sciences, University of the Philippines, 1991.
एमएलए (9वां संस्करण) प्रशस्ति पत्रManuel, Esperidion Arsenio. Subterranean Structures in Intramuros, the Walled City of Manila: A Germinal Paper. Manila Studies Program, College of Arts and Sciences, University of the Philippines, 1991.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.