1. Child CD (1911) Discharge from Hot CaO. Phys Rev 32(5):492–511
2. Carr CG (2004) Space charge limited emission studies using Coulomb’s Law. M.S. thesis, Naval Post Graduate School, Monterey
3. Langmuir I, Blodgett KB (1924) Current limited by space charge between concentric spheres. Phys Rev 23:49
4. Stoyanov DG (2006) Planar vacuum diode with monoenergetic electrons. J Appl Electromagn 8(1–2):35–48
5. Stoyanov DG (2010) Analytical solution to the Langmuir spherical problem. arXiv:1008.4935v1 [physics.gen-ph]