Lehrer, K. (1990). Theory of knowledge. Routledge.
Chicago-čujuhus (17. p.)Lehrer, Keith. Theory of Knowledge. London: Routledge, 1990.
MLA-čujuhus (9. p.)Lehrer, Keith. Theory of Knowledge. Routledge, 1990.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.