Temporal stability and absolute composition issues in molecular beam epitaxy of AlGaAs/GaAs THz QCLI. S. Vasil’evskii, A.N. Vinichenko, M.M. Grekhov, V.V. Saraykin, A.N. Klochkov, N.I. Kargin, R.A. Khabibullin and S.S. PushkarevEPJ Web Conf., 195 (2018) 04006DOI: https://doi.org/10.1051/epjconf/201819504006