S. Behrouzinia, M. Zand, A. Namdar, and A. Moghimi, Trans., “The effect of operational parameters on the output power of copper vapor laser with small-bore tube”, Int.J. Fundam. Phys. Sci, vol. 1, no. 3, pp. 60–63, Sep. 2011, doi: 10.14331/ijfps.2011.330015.