Note 8 — 8. Schiefe Ebene, Keil und Schraube.
Reading edition
Globus, Band 79 und 80; M. P. Porsild, The principle of the screw in the technique of the Eskimo. American Anthropologist. N. S. Vol. 17, Nr. 1; B. Laufer, The Eskimo screw as a Culture-Historical Problem, ebenda, Nr. 2; Horwitz, a. a. O.