Não informado. (1915). Annals of the Dearborn Observatory of the Northwestern University. Dearborn Observatory of the Northwestern University.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Annals of the Dearborn Observatory of the Northwestern University. Evanston, Ill: Dearborn Observatory of the Northwestern University, 1915.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Annals of the Dearborn Observatory of the Northwestern University. Dearborn Observatory of the Northwestern University, 1915.
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