Collect. Czech. Chem. Commun.
1973, 38, 1459-1462
https://doi.org/10.1135/cccc19731459
Electronic spectra of azulene mononegative and monopositive ions and semiempirical open shell PPP-like calculations
I. Nykl, A. Fojtík, P. Hobza, P. Čársky, R. Zahradník and T. Shida