Sobel, D. (1996). Longitude: The true story of a lone genius who solved the greatest scientific problem of his time. Fourth Estate.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSobel, Dava. Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. London: Fourth Estate, 1996.
एमएलए (9वां संस्करण) प्रशस्ति पत्रSobel, Dava. Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. Fourth Estate, 1996.
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