1. Clar, E., "Aromatische Kohlenwasserstoffe", 20 (Springer-Verlag, 1941).
2. Sirkin, J. K., and Diatkina, M. E., Bull. Acad. Sci. U.R.S.S., Cl. Sci. Chim., 153 (1946). Brit. Abstr., AI, 365 (1946). The view of these authors was supported, and in some cases an even greater stability of the higher methyl-acenes was predicted in private communications from other workers.
3. Ber., 56, 1619 (1923).
4. Clar, E., Ber., 75, 1271 (1942). Compare Fieser, L. F., J. Amer. Chem. Soc., 53, 2329 (1931).
5. Marschalk, Ch., Bull. Soc. Chim., (5), 4, 1549 (1937).