Borlaza, C., Mejia, J., & Sarabia, A. (1991). A Systems study of R.A. hats. College of Engineering.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रBorlaza, Carlo, Jonstein Mejia, और Allan Sarabia. A Systems Study of R.A. Hats. Diliman, Quezon City: College of Engineering, 1991.
एमएलए (9वां संस्करण) प्रशस्ति पत्रBorlaza, Carlo, et al. A Systems Study of R.A. Hats. College of Engineering, 1991.
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