1. Kolka, A.J., J. Org. Chem. 22:988 (1957).
2. Loev, B., and J.T. Massengale, J. Org. Chem. 22:988 (1957).
3. Dijkstra, R., U.S. Patent 2,874,193.
4. Weingarten, E., Brennst. Chem. 42:361 (1961).
5. Cross, J.M., and M.E. Chiddix, U.S. Patent 2,536,976.