1. D. O. Gorelik et al., Izmeritel'. Tekh., No. 6 (1975).
2. E. F. Dolinskii, The Processing of Results of Measurements [in Russian], Standards Publishing House, Moscow (1973).
3. A. G. Anikin and G. M. Dugacheva, Determining the Purity of Organic Substances [in Russian], MGU, Moscow (1973).
4. P. Shuftan, An Analysis of Gases in Technology [in Russian], GÉI, Moscow-Leningrad (1933).
5. Argon for Electrical Heating Tubes [Russian translation], Methods of Experiment, Japanese Standard (1953).