Isomorphous phase transition and orientational freezing in hexagonal mixed crystal C70(1-x)C60x. A pseudospin modelP. Zieliński, W. Schranz, D. Havlik and A. V. KitykEur. Phys. J. B, 24 2 (2001) 155-165DOI: https://doi.org/10.1007/s100510170003