Ingbretsen, R. M. (1988). Hillyard: The engines and the craftsmen. Inland Empire Railway Historical Society.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रIngbretsen, Roger M. Hillyard: The Engines and the Craftsmen. Inland Empire Railway Historical Society, 1988.
एमएलए (8वां संस्करण) प्रशस्ति पत्रIngbretsen, Roger M. Hillyard: The Engines and the Craftsmen. Inland Empire Railway Historical Society, 1988.
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