Ernest, J. W., & Ashmun, R. D. (1973). Salesmanship Fundamentals (4th ed.). McGraw-Hill.
Chicago Edition CitationErnest, John W., i Richard D. Ashmun. Salesmanship Fundamentals. 4th ed. New York: McGraw-Hill, 1973.
Cita MLAErnest, John W., i Richard D. Ashmun. Salesmanship Fundamentals. 4th ed. McGraw-Hill, 1973.
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