Não informado. (1966). Research Paper NC. North Central Forest Experiment Station.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Research Paper NC. Saint Paul, Minn: North Central Forest Experiment Station, 1966.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Research Paper NC. North Central Forest Experiment Station, 1966.
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