P. G. Eliseev, V. G. Smagley, and M. Osiński, "Threshold current density in optimized UV diode lasers based on gallium nitride,"
in Conference on Lasers and Electro-Optics, J. Bowers, D. Miller, D. Scifres, and A. Weiner, eds.,
Vol. 9 of OSA Technical Digest
(Optical Society of America, 1996), paper CThP4.