Channell, James E. T.; Ogg, James G.; Lowrie, W. (1982): Geomagnetic polarity in the Early Cretaceous and Jurassic. Royal Society of London, London, United Kingdom, In: Runcorn, S. K. (editor), Creer, K. M., Jacobs, J. A., The Earth's core; its structure, evolution and magnetic field; discussion, 306 (1492), 137-146, georefid:1985-007991