Coba jelasin Catatan dari Kereta kuda yang menunjuk ke selatan dong

The Chinese South-Seeking chariot: A simple mechanical device for visualizing curvature and parallel transport M. Santander, American Journal of Physics – September 1992 – Volume 60, Issue 9, pp. 782–787

Needham, Joseph (1986). Science and Civilization in China: Volume 4, Part 2. Taipei: Caves Books, Ltd.

Kit Williams, Engines of Ingenuity, Gingko Press (February 2002),