1. Chang, C.D. and Lang,W.H., Patent US 4062905, 1977.
2. White, M.V.. Patent US 3984106, 1974.
3. Butter, S.A., Jurewicz, A.T., and Kaeding, W.W., Patent US 3894107, 1974.
4. Chang, C.D. and Silvestri, A.J., J. Catal., 1977, vol. 47, no. 2, pp. 249–259. https://doi.org/10.1016/0021-9517(77)90172-5
5. Tian, P., Wei, Y., Ye, M., and Liu, Z., ACS Catal., 2015, vol. 5, no. 3, pp. 1922–-1938. https://doi.org/10.1021/acscatal.5b00007