V.P. Gnezdilov, Yu.G. Pashkevich, A.V. Yeremenko, P. Lemmens, G. Guntherodt, S.V. Shiryaev, G.L. Bychkov, and S.N. Barilo, Phonon Raman scattering in LaMn_1-xCo_xO₃ (x = 0, 0.2, 0.3, 0.4, and 1.0), Low Temp. Phys. 29, (2003) [Fiz. Nizk. Temp. 29, 1269-1272, (2003)].