Hopson, B. (1994). Twelve steps to success through service. Excel.
Chicago-čujuhus (17. p.)Hopson, Barrie. Twelve Steps to Success Through Service. New Delhi: Excel, 1994.
MLA-čujuhus (9. p.)Hopson, Barrie. Twelve Steps to Success Through Service. Excel, 1994.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.