Gaya APA

Ascher, W., Overholt, W, H. (1983). Strategic planning and forecasting : political risk and economic opportunity . New York: John Wiley.

Gaya MLA

Ascher, William., Overholt, William, H.. "Strategic planning and forecasting : political risk and economic opportunity". New York: John Wiley, 1983. Buku/Printed Material.