Hatfield, N. J. (1978). Basic market, research techniques for transit systems. U.S. Department of Commerce.
Chicago-čujuhus (17. p.)Hatfield, Nancy J. Basic Market, Research Techniques for Transit Systems. Austin: U.S. Department of Commerce, 1978.
MLA-čujuhus (9. p.)Hatfield, Nancy J. Basic Market, Research Techniques for Transit Systems. U.S. Department of Commerce, 1978.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.