Zemke,Ron. (1989). The service edge: 101 companies that profit from customer care. Penguin books.
Chicago Style (17th ed.) CitationZemke,Ron. The Service Edge: 101 Companies That Profit from Customer Care. Canada: Penguin books, 1989.
MLA (9th ed.) CitationZemke,Ron. The Service Edge: 101 Companies That Profit from Customer Care. Penguin books, 1989.
Warning: These citations may not always be 100% accurate.