Koch, A. R. (1986). Economic principles: Growth and environment. Avi.
Chicago-čujuhus (17. p.)Koch, A. Robert. Economic Principles: Growth and Environment. Westport, Conn.: Avi, 1986.
MLA-čujuhus (9. p.)Koch, A. Robert. Economic Principles: Growth and Environment. Avi, 1986.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.