Graham Ian. Tough Machines (Discovery explore your world). Miles Kelly.
Chicago-čujuhus (17. p.)Graham Ian. Tough Machines (Discovery Explore Your World). Miles Kelly.
MLA-čujuhus (9. p.)Graham Ian. Tough Machines (Discovery Explore Your World). Miles Kelly.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.