Spencer, L. M. (1993). Competence at Work (11th.). McGraw-Hill.
Chicago-čujuhus (17. p.)Spencer, Lyle M. Competence at Work. 11th. Singapore: McGraw-Hill, 1993.
MLA-čujuhus (9. p.)Spencer, Lyle M. Competence at Work. 11th. McGraw-Hill, 1993.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.