1. K. Higasi, H. Baba, and A. Rembaum, Quantum Organic Chemistry [Russian translation], Mir (1967).
2. A. M. Tyul'maliev and I. V. Stankevich, Zh. Fiz. Khim.,46, 2710 (1972).
3. I. Hinze and H. H. Jaffe, J. Am. Chem. Soc.,84, 640 (1962).
4. N. Mataga and K. Nichimoto, J. Chem. Phys.,12, 335 (1957).
5. R. Pariser and R. G. Parr, ibid.,21, 767 (1953).