1. J. ALIZON, J.P. BLANC, H. ROBERT, C. FABRE, H. STRZELECKA, J. RIVORY, C. WEYL, Proceedings of the Conference on Organic Conductors and Semiconductors, Siofok, Maison d'éditions de l'Académie des Sciences de Hongrie, Hongrie (1976), p. 563.
2. For synthesis of dipyranylidene donors, see C. FABRE, R. FUGNITTO and H. STRZELECKA, Comptes Rendus Acad. Sci. 282, C, 175 (1976).
3. B.A. SCOTT, S.J. La PLACA, J.B. TORRANCE, B.D. SILVERMAN and B. WELBER, JACS 99, 6631 (1977), and references therein.
4. R.B. SOMOANO, S.P.S. YEN, V. HADEK, S.K. KHANNA, M. NOVOTNY, T. DATTA, A.M. HERMANN, J.A. WOOLLAM, Phys. Rev. B 17, 2853 (1978), and references therein.
5. S.P. ZOLOTOUKHIN, V.F. KAMINSKI, A.I. KOTOV, M.L. KHIDEKEL, R.P. SHIBAIEVA and E.B. IAKOUBSKI, Izv. Ak. Nauk SSSR, Seria Chim. 8, 1816 (1978).