Haapala, P. (1936). On serpentine rocks in northern Karelia: With 21 figures in text and two maps. Government Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHaapala, Paavo. On Serpentine Rocks in Northern Karelia: With 21 Figures in Text and Two Maps. Helsinki: Government Press, 1936.
एमएलए (8वां संस्करण) प्रशस्ति पत्रHaapala, Paavo. On Serpentine Rocks in Northern Karelia: With 21 Figures in Text and Two Maps. Government Press, 1936.
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