Koch, R. (1955). The book of signs. Dover.
Chicago-čujuhus (17. p.)Koch, Rudolf. The Book of Signs. Nueva York: Dover, 1955.
MLA-čujuhus (9. p.)Koch, Rudolf. The Book of Signs. Dover, 1955.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.