Gaya APA
Drucker, P, E. (1985).
(PASCA) Innovation and Entrepreneurship : Practice and Principles (Edisi 1).
USA:
Perenial Library.
Gaya MLA
Drucker, Peter, E..
"(PASCA) Innovation and Entrepreneurship : Practice and Principles".
Edisi 1
USA:
Perenial Library,
1985.
.