Humphrey, J. (2021). High Performance. Penguin.
Chicago-čujuhus (17. p.)Humphrey, Jake. High Performance. Penguin, 2021.
MLA-čujuhus (9. p.)Humphrey, Jake. High Performance. Penguin, 2021.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.