W. Kohn and L. J. Sham, “Self-Consistent Equations Including Exchange and Correlation Effects,” Physical Review Journal, Vol. 140, No. 4A, 1965, pp. A1133-A1138.
 S. Daiuk, M. Sob and A. Rubaszek, “Theoretical calculations of positron annihilation with rare gas core electrons in simple and transition metals,” Journal of Physics F: Metal Physics B, Vol. 43, No. 4, 1991, pp. 2580-2593.
 M. J. Puska and R. M. Nieminen, “Defect Spectroscopy with Positron: A General Calculation Method,” Journal of Physics F: Metal Physics, 1983, pp. 333-346.
 G. F. Gribakin and C. M. R. Lee, “Application of the zero-range potential model to positron annihilation on molecules,” Nuclear Instruments and Methods in Physics Research B, Vol. 247, No. 1, 2006, pp. 31-37.
 E. M. Hassan, B. A. A. Balboul and M. A. Abdel-Rahman, “Probing the Phase Transition in Nanocrystalline TiO2 Powders by Positron Lifetime (PAL) Technique,” Defect and Diffusion Forum, Vol. 319-320, 2011, pp 151-159.