الكسارة - ويكيبيديا
Viking Penguin,Inc., New York, NY, U.S.A., (1985). ص. 352 (indexed). ISBN 9780670804832. مؤرشف من الأصل في 29 فبراير 2020. Within a few years, however, the cost was reduced by nine-tenths as it was found cast-iron cylinders could be produced with sufficient accuracy. ^ Burke, James, "Connections", page 170.
