M.A. Strzhemechny and I.V. Legchenkova, Novel mechanism of the negative thermal expansion of doped fullerite C₆₀, Low Temp. Phys. 36, (2010) [Fiz. Nizk. Temp. 36, 470-473, (2010)] DOI: https://doi.org/10.1063/1.3432243.