Παραπομπή APA

National productivity council. (1965). Refractories industry in USA, Britain and West Germany. National productivity council.

Παραπομπή Chicago Style

National productivity council. Refractories Industry in USA, Britain and West Germany. New Delhi: National productivity council, 1965.

Παραπομπή MLA

National productivity council. Refractories Industry in USA, Britain and West Germany. National productivity council, 1965.