Drucker, P. F. (2017). The Theory of the Business. Harvard Business Review Press.
Lua i Stíl Chicago (17ú heag.)Drucker, Peter F. The Theory of the Business. Boston, Massachesutts: Harvard Business Review Press, 2017.
Lua MLA (9ú heag.)Drucker, Peter F. The Theory of the Business. Harvard Business Review Press, 2017.
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