Gaya APA

[et.al], S, Y. (2014). The Role of External Environment in Upper Echelons Theory: A Review of Existing Literature and Future Research Directions . : The Author.

Gaya MLA

[et.al], Sibel, Yamak. "The Role of External Environment in Upper Echelons Theory: A Review of Existing Literature and Future Research Directions". : The Author, 2014. e-journal.