Haapala, P. (1936). On serpentine rocks in northern Karelia: With 21 figures in text and two maps. Government Press.
Chicago-referens (17:e uppl.)Haapala, Paavo. On Serpentine Rocks in Northern Karelia: With 21 Figures in Text and Two Maps. Helsinki: Government Press, 1936.
MLA-referens (8:e uppl.)Haapala, Paavo. On Serpentine Rocks in Northern Karelia: With 21 Figures in Text and Two Maps. Government Press, 1936.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.