1. Billyeald, D., and Patrick, J. W. (1975). Extended Abstr. Bienn. Conf. Carbon, 12th, Pittsburgh pp. 147-148.
2. Blayden, H. E. (1966). Year-Book Coke Oven Managers' Assoc. pp. 197-216.
3. Blayden, H.E., Gibson, J., and Riley, H. L. (1944). Proc. Conf. Ultrafine Struct. Coals Cokes, London 1943 pp. 176-231.