Espina, R. L. (2005). Breakthrough in biofuel program. IN The southern beat [column]. Philippine Star.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रEspina, Rolly L. "Breakthrough in Biofuel Program. IN The Southern Beat [column]." Philippine Star 2005.
एमएलए (9वां संस्करण) प्रशस्ति पत्रEspina, Rolly L. "Breakthrough in Biofuel Program. IN The Southern Beat [column]." Philippine Star, 2005.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.