1. Adamson, A.J., Whittet, D.C.B., Bode, M.F., Longmore, A.J., Roche, P.F., McFadzean, A.D., Geballe, T.R., Aitken, D.K.: 1988, inDust in the Universe, eds. Bailey, M.E. and Williams, D.A., Cambridge University Press, p.61
2. Allamandola, L.J., Sandford, S.A.: 1988, inDust in the Universe, eds. Bailey, M.E. and Williams, D.A., Cambridge University Press, p.229
3. Banwell, C.N.: 1983,Fundamentals of Molecular Spectroscopy, 3rd Edition (McGraw-Hill)
4. Barlow, M.J.: 1978,Monthly Notices Roy. Astron. Soc. 183, 417
5. Black, J.H., Willner, S.P.: 1984,Astrophys. J. 279, 673